The Challenge: Slow List Building From CRMs

Many sales organizations sit on massive amounts of CRM data, yet building a usable outreach list still takes days. Reps and ops teams spend hours exporting accounts, stacking filters, correcting obvious errors, and manually stitching together contacts across tools. By the time a segment is ready, the window of opportunity for a campaign is often already closing.

Traditional approaches rely on manual work in tools that were never designed for modern, high-velocity sales operations. CRMs offer basic filtering, but not intelligent segment discovery, data enrichment, or smart deduplication. Excel-based workflows turn into fragile monster spreadsheets that break easily, produce inconsistent results, and are nearly impossible to reuse. As volumes grow, list building becomes a bottleneck instead of an enabler.

The impact is significant: campaigns are delayed, sales teams target the wrong accounts, and high-intent leads remain buried under outdated, incomplete, or duplicate records. Dirty lists lead to higher bounce rates, lower sender reputation, and reps losing trust in the data they are given. Competitors who move faster and use cleaner targeting win deals earlier in the buying cycle, while your team is still cleaning CSVs.

The good news: this problem is very solvable. With the latest generation of AI models like Claude, companies can automate list cleansing, segmentation, and enrichment directly from CRM exports. At Reruption, we’ve seen how an AI-first approach to internal workflows can replace fragile spreadsheets with robust automations in a matter of weeks. In the rest of this guide, we’ll break down practical, concrete ways to use Claude to turn slow list building into a fast, reliable part of your sales engine.

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Our Assessment

A strategic assessment of the challenge and high-level tips how to tackle it.

From Reruption’s perspective, the real opportunity is not just to “speed up” today’s manual CRM workflows, but to rethink sales list building with Claude as a core capability. We’ve implemented AI solutions across complex organisations and repeatedly seen that when you treat models like Claude as part of your sales operations stack—rather than a one-off experiment—you unlock cleaner data, better targeting, and a much faster top-of-funnel.

Think in Systems, Not One-Off List Cleanups

Most sales teams first try AI on an ad-hoc basis: upload a CSV, get a cleaned file back, and move on. That can be a useful experiment, but it doesn’t fix the systemic issue that your CRM list building process is broken by design. Strategically, you want to define a repeatable pipeline where Claude sits between your raw CRM data and every outbound campaign, automatically preparing lists to a consistent standard.

This means mapping out your end-to-end flow—from data capture, to CRM structure, to outreach tools—and deciding where Claude should take ownership: enrichment, deduplication, segmentation, or all three. When you treat Claude as a stable component in your sales tech stack, you get compounding benefits: every campaign makes the system smarter, every exception becomes a rule, and sales teams stop reinventing the wheel in spreadsheets.

Start with One Critical Segment Before Scaling

Instead of trying to automate every segment and market at once, choose one high-impact segment as your pilot: for example, mid-market accounts in a specific region or companies with a specific product usage pattern. This gives you a clear sandbox to define what a “good list” actually looks like: required fields, ICP criteria, data quality thresholds, and acceptable error rates.

With a tightly scoped pilot, your sales leaders, ops, and data teams can align on definitions (what is a duplicate, what counts as a decision-maker, how old can data be) while seeing immediate value. This approach also de-risks AI adoption: you can measure the uplift on a single segment—faster campaign launch, more meetings booked—before committing budget and organisational energy to wider rollout.

Align Sales, RevOps, and Data Owners Early

Claude will sit at the intersection of sales operations, data ownership, and tooling. If these stakeholders are not aligned, you risk building an elegant AI workflow that no one uses. Sales needs clear SLAs for when lists are ready, RevOps defines business rules and field mappings, and data owners ensure compliance and governance.

Strategically, bring these groups together at the design stage. Agree on where the “source of truth” lives, which fields Claude is allowed to update or enrich, and how exceptions are handled. When ownership is clear, AI becomes a trusted extension of the team rather than a black box that everyone is suspicious of.

Design for Explainability and Human Oversight

Even with strong models like Claude, sales list building remains a human-critical process. Reps and sales managers must understand why certain accounts are in a segment, why others are excluded, and how duplicates were resolved. If the process feels opaque, they’ll revert to manual lists—even if the AI lists are statistically better.

Build explainability into your approach. For example, require Claude to output a short rationale for each account’s inclusion and the rules it applied. Decide which steps remain human-reviewed (e.g., final approval of tier-1 accounts) and where full automation is acceptable (e.g., cleaning job titles). This oversight ensures quality while building organisational trust in AI-assisted decision-making.

Manage Risk Around Data Privacy and Tool Sprawl

Sending CRM exports into various tools can create data privacy and governance risks, especially in regulated environments. Strategically, decide early whether Claude will run in a controlled environment (e.g., via API inside your infrastructure) and what data is allowed to leave your core systems. This should be coordinated with your security and legal teams, not done informally by individual reps.

In parallel, avoid tool sprawl. If every team spins up its own AI list-building shortcuts, you end up with inconsistent processes and unknown data flows. Instead, centralise your Claude usage into a few well-governed workflows owned by RevOps or a central AI team, and make those the standard across the sales organisation.

Used strategically, Claude can turn CRM list building from a slow, manual bottleneck into a fast, explainable, and governable process that reliably feeds your sales funnel. The hard part is less about prompts and more about designing the right workflows, guardrails, and ownership around the model. At Reruption, we specialise in building these AI-first capabilities inside organisations—if you want to see how a Claude-powered list-building pipeline would work with your real CRM data, our PoC format is a pragmatic way to test it with a functioning prototype before you scale. Feel free to reach out when you’re ready to explore that step.

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Real-World Case Studies

From Fintech to Healthcare: Learn how companies successfully use Claude.

Klarna

Fintech

Klarna, a leading fintech BNPL provider, faced enormous pressure from millions of customer service inquiries across multiple languages for its 150 million users worldwide. Queries spanned complex fintech issues like refunds, returns, order tracking, and payments, requiring high accuracy, regulatory compliance, and 24/7 availability. Traditional human agents couldn't scale efficiently, leading to long wait times averaging 11 minutes per resolution and rising costs. Additionally, providing personalized shopping advice at scale was challenging, as customers expected conversational, context-aware guidance across retail partners. Multilingual support was critical in markets like US, Europe, and beyond, but hiring multilingual agents was costly and slow. This bottleneck hindered growth and customer satisfaction in a competitive BNPL sector.

Lösung

Klarna partnered with OpenAI to deploy a generative AI chatbot powered by GPT-4, customized as a multilingual customer service assistant. The bot handles refunds, returns, order issues, and acts as a conversational shopping advisor, integrated seamlessly into Klarna's app and website. Key innovations included fine-tuning on Klarna's data, retrieval-augmented generation (RAG) for real-time policy access, and safeguards for fintech compliance. It supports dozens of languages, escalating complex cases to humans while learning from interactions. This AI-native approach enabled rapid scaling without proportional headcount growth.

Ergebnisse

  • 2/3 of all customer service chats handled by AI
  • 2.3 million conversations in first month alone
  • Resolution time: 11 minutes → 2 minutes (82% reduction)
  • CSAT: 4.4/5 (AI) vs. 4.2/5 (humans)
  • $40 million annual cost savings
  • Equivalent to 700 full-time human agents
  • 80%+ queries resolved without human intervention
Read case study →

Shell

Energy

Unplanned equipment failures in refineries and offshore oil rigs plagued Shell, causing significant downtime, safety incidents, and costly repairs that eroded profitability in a capital-intensive industry. According to a Deloitte 2024 report, 35% of refinery downtime is unplanned, with 70% preventable via advanced analytics—highlighting the gap in traditional scheduled maintenance approaches that missed subtle failure precursors in assets like pumps, valves, and compressors. Shell's vast global operations amplified these issues, generating terabytes of sensor data from thousands of assets that went underutilized due to data silos, legacy systems, and manual analysis limitations. Failures could cost millions per hour, risking environmental spills and personnel safety while pressuring margins amid volatile energy markets.

Lösung

Shell partnered with C3 AI to implement an AI-powered predictive maintenance platform, leveraging machine learning models trained on real-time IoT sensor data, maintenance histories, and operational metrics to forecast failures and optimize interventions. Integrated with Microsoft Azure Machine Learning, the solution detects anomalies, predicts remaining useful life (RUL), and prioritizes high-risk assets across upstream oil rigs and downstream refineries. The scalable C3 AI platform enabled rapid deployment, starting with pilots on critical equipment and expanding globally. It automates predictive analytics, shifting from reactive to proactive maintenance, and provides actionable insights via intuitive dashboards for engineers.

Ergebnisse

  • 20% reduction in unplanned downtime
  • 15% slash in maintenance costs
  • £1M+ annual savings per site
  • 10,000 pieces of equipment monitored globally
  • 35% industry unplanned downtime addressed (Deloitte benchmark)
  • 70% preventable failures mitigated
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Unilever

Human Resources

Unilever, a consumer goods giant handling 1.8 million job applications annually, struggled with a manual recruitment process that was extremely time-consuming and inefficient . Traditional methods took up to four months to fill positions, overburdening recruiters and delaying talent acquisition across its global operations . The process also risked unconscious biases in CV screening and interviews, limiting workforce diversity and potentially overlooking qualified candidates from underrepresented groups . High volumes made it impossible to assess every applicant thoroughly, leading to high costs estimated at millions annually and inconsistent hiring quality . Unilever needed a scalable, fair system to streamline early-stage screening while maintaining psychometric rigor.

Lösung

Unilever adopted an AI-powered recruitment funnel partnering with Pymetrics for neuroscience-based gamified assessments that measure cognitive, emotional, and behavioral traits via ML algorithms trained on diverse global data . This was followed by AI-analyzed video interviews using computer vision and NLP to evaluate body language, facial expressions, tone of voice, and word choice objectively . Applications were anonymized to minimize bias, with AI shortlisting top 10-20% of candidates for human review, integrating psychometric ML models for personality profiling . The system was piloted in high-volume entry-level roles before global rollout .

Ergebnisse

  • Time-to-hire: 90% reduction (4 months to 4 weeks)
  • Recruiter time saved: 50,000 hours
  • Annual cost savings: £1 million
  • Diversity hires increase: 16% (incl. neuro-atypical candidates)
  • Candidates shortlisted for humans: 90% reduction
  • Applications processed: 1.8 million/year
Read case study →

Airbus

Aerospace

In aircraft design, computational fluid dynamics (CFD) simulations are essential for predicting airflow around wings, fuselages, and novel configurations critical to fuel efficiency and emissions reduction. However, traditional high-fidelity RANS solvers require hours to days per run on supercomputers, limiting engineers to just a few dozen iterations per design cycle and stifling innovation for next-gen hydrogen-powered aircraft like ZEROe. This computational bottleneck was particularly acute amid Airbus' push for decarbonized aviation by 2035, where complex geometries demand exhaustive exploration to optimize lift-drag ratios while minimizing weight. Collaborations with DLR and ONERA highlighted the need for faster tools, as manual tuning couldn't scale to test thousands of variants needed for laminar flow or blended-wing-body concepts.

Lösung

Machine learning surrogate models, including physics-informed neural networks (PINNs), were trained on vast CFD datasets to emulate full simulations in milliseconds. Airbus integrated these into a generative design pipeline, where AI predicts pressure fields, velocities, and forces, enforcing Navier-Stokes physics via hybrid loss functions for accuracy. Development involved curating millions of simulation snapshots from legacy runs, GPU-accelerated training, and iterative fine-tuning with experimental wind-tunnel data. This enabled rapid iteration: AI screens designs, high-fidelity CFD verifies top candidates, slashing overall compute by orders of magnitude while maintaining <5% error on key metrics.

Ergebnisse

  • Simulation time: 1 hour → 30 ms (120,000x speedup)
  • Design iterations: +10,000 per cycle in same timeframe
  • Prediction accuracy: 95%+ for lift/drag coefficients
  • 50% reduction in design phase timeline
  • 30-40% fewer high-fidelity CFD runs required
  • Fuel burn optimization: up to 5% improvement in predictions
Read case study →

NYU Langone Health

Healthcare

NYU Langone Health, a leading academic medical center, faced significant hurdles in leveraging the vast amounts of unstructured clinical notes generated daily across its network. Traditional clinical predictive models relied heavily on structured data like lab results and vitals, but these required complex ETL processes that were time-consuming and limited in scope. Unstructured notes, rich with nuanced physician insights, were underutilized due to challenges in natural language processing, hindering accurate predictions of critical outcomes such as in-hospital mortality, length of stay (LOS), readmissions, and operational events like insurance denials. Clinicians needed real-time, scalable tools to identify at-risk patients early, but existing models struggled with the volume and variability of EHR data—over 4 million notes spanning a decade. This gap led to reactive care, increased costs, and suboptimal patient outcomes, prompting the need for an innovative approach to transform raw text into actionable foresight.

Lösung

To address these challenges, NYU Langone's Division of Applied AI Technologies at the Center for Healthcare Innovation and Delivery Science developed NYUTron, a proprietary large language model (LLM) specifically trained on internal clinical notes. Unlike off-the-shelf models, NYUTron was fine-tuned on unstructured EHR text from millions of encounters, enabling it to serve as an all-purpose prediction engine for diverse tasks. The solution involved pre-training a 13-billion-parameter LLM on over 10 years of de-identified notes (approximately 4.8 million inpatient notes), followed by task-specific fine-tuning. This allowed seamless integration into clinical workflows, automating risk flagging directly from physician documentation without manual data structuring. Collaborative efforts, including AI 'Prompt-a-Thons,' accelerated adoption by engaging clinicians in model refinement.

Ergebnisse

  • AUROC: 0.961 for 48-hour mortality prediction (vs. 0.938 benchmark)
  • 92% accuracy in identifying high-risk patients from notes
  • LOS prediction AUROC: 0.891 (5.6% improvement over prior models)
  • Readmission prediction: AUROC 0.812, outperforming clinicians in some tasks
  • Operational predictions (e.g., insurance denial): AUROC up to 0.85
  • 24 clinical tasks with superior performance across mortality, LOS, and comorbidities
Read case study →

Best Practices

Successful implementations follow proven patterns. Have a look at our tactical advice to get started.

Use Claude to Define and Refine Your ICP Segmentation Logic

Before automating list creation, start by having Claude help you formalise your ideal customer profile (ICP) and segment rules using real CRM data. Export a representative sample of past opportunities (wins and losses) with firmographics, deal size, and status. Feed this into Claude and ask it to cluster accounts and surface patterns you might be missing.

Example prompt to Claude:
You are a sales operations analyst.
I will provide a CSV sample of accounts and opportunities with these fields:
- Industry, Company size (employees & revenue)
- Region, Tech stack indicators
- Deal size, Win/Loss, Sales cycle length

1) Cluster the accounts into 3-6 segments based on similarity.
2) For each segment, describe the common traits in plain language.
3) Identify which segments have the highest win rates and fastest cycles.
4) Propose clear, machine-usable ICP rules (if/then style) for our "Tier 1" and "Tier 2" targets.

Use Claude’s output as a draft, then refine with your sales leadership. Once agreed, these ICP rules become the backbone of subsequent automated list-building prompts and workflows.

Automate CRM Export Cleaning and Normalisation

Once you have a consistent ICP definition, you can use Claude to clean and normalise raw CRM exports before they ever reach reps or outbound tools. Export your target accounts and contacts as CSV from your CRM and pass them to Claude with explicit rules for standardisation (titles, countries, phone formats, etc.).

Example prompt to Claude:
You are a data cleaning assistant for sales operations.
I will send you a CSV of accounts and contacts.
Please:
- Standardise job titles into a new column: Seniority (C-level, VP, Director, Manager, IC)
- Normalise country names to ISO country codes
- Flag likely personal email addresses in a new column (is_personal = yes/no)
- Identify and label missing critical fields (e.g., missing company size, missing email)
Return the cleaned data as a CSV structure in your response.

You can wire this into a simple automation (e.g., via an integration platform or custom script using the Claude API) so that every export passes through the same cleaning step, reducing manual corrections and making lists consistent across teams.

Use Claude for Smart Deduplication with Business Rules

Standard deduplication in CRMs often uses simple exact matches on email or company name, which misses many real-world duplicates and sometimes merges records that should remain separate. Claude can apply fuzzy matching plus business logic to decide what should be merged and how.

Example prompt to Claude:
You are a CRM deduplication assistant.
I will provide a CSV with potential duplicate records (grouped by similar company or email).
For each group:
- Decide whether the records are true duplicates or separate entities.
- If duplicates, choose the best master record based on:
  1) Most complete data
  2) Newest "last activity" date
  3) Presence of an open opportunity
- Propose a merged record with consolidated fields.
- Explain in 1-2 sentences why you decided to merge or not.
Output a table with: group_id, action (merge/keep), master_id, merged_record.

These decisions can then be reviewed by RevOps in a batch before being applied back into the CRM, striking a balance between automation and control.

Generate Campaign-Ready Segments and Messaging Hints

Beyond raw lists, Claude can help you produce campaign-ready segments that include not just who to contact, but why they’re relevant and how to position your message. After cleaning and deduplication, send Claude the final list and ask it to group accounts into micro-segments with tailored messaging angles.

Example prompt to Claude:
You are a B2B sales strategist.
Here is a cleaned CSV of target accounts with industry, size, and key fields.
1) Group the accounts into 3-8 micro-segments based on similar traits and likely pain points.
2) For each segment, provide:
   - Segment name
   - 2-3 key characteristics (from the data)
   - Main value proposition angle we should use in outbound
   - 2 subject line ideas for email
3) Assign each account a segment_name.
Return a JSON with segments and an updated list of accounts with their segment_name.

This structure can be imported into your outbound tool, where reps or marketing can quickly adapt the suggested angles into actual sequences without starting from a blank page.

Enrich Incomplete Records with Publicly Available Signals

Many CRM records are missing crucial fields like company size, industry, or role seniority. Within your compliance limits, you can use Claude to enrich leads with contextual information derived from company descriptions, websites, or other internal data you’re allowed to use. For example, you might store a short company description or LinkedIn snippet and let Claude infer missing attributes.

Example prompt to Claude:
You are a lead enrichment assistant.
For each record I send with "company_name", "company_description" and "job_title":
- Infer the most likely industry from a fixed list we use (I will provide it).
- Classify company size band: 1-50, 51-200, 201-1000, 1001-5000, 5000+.
- Determine seniority level from job_title (C-level, VP, Director, Manager, IC).
Output a CSV-style table with the original ID and the inferred fields.

By standardising these enrichments through Claude, you can drastically reduce the number of “incomplete” leads that would otherwise be excluded from campaigns or require manual research.

Measure Performance and Iterate Prompts Like a Product

To get durable value, treat your Claude list-building workflows as living products, not one-time experiments. Define clear KPIs: time from list request to delivery, percentage of records missing key fields, bounce rate of campaigns using AI-prepared lists, and meetings booked per 100 contacts.

Set up a simple feedback loop: after each campaign, compare these KPIs to historical baselines and look for failure patterns (e.g., too many junior contacts, wrong industries slipping in). Feed a sample of problematic records back into Claude with explicit questions about what went wrong and how to adjust the rules. Over a few iterations, your prompts and business logic will stabilise and become a reliable asset for the entire sales organisation.

When executed well, these practices can realistically cut list preparation time by 50–80%, reduce bounce rates by 20–30%, and free up sales and RevOps teams to focus on strategy and conversations instead of spreadsheets. The exact numbers will depend on your starting point, but the pattern is consistent: cleaner lists, faster campaigns, and a stronger, more predictable top-of-funnel.

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Frequently Asked Questions

Claude accelerates list building by automating the tedious steps that usually slow sales teams down. Instead of manually filtering, cleaning, and deduplicating exports, you send the CRM data to Claude with clear rules for segmentation, normalisation, and deduplication. It returns a campaign-ready list with consistent formats, flagged issues, and even suggested micro-segments or messaging angles.

In practice, this can transform a multi-day process involving several people into a repeatable workflow that runs in minutes, with RevOps simply reviewing edge cases instead of doing all the work manually.

You don’t need a large data science team to get started. The core requirements are: someone who understands your sales processes and ICP (typically Sales or RevOps), access to your CRM exports, and basic technical skills to connect Claude via API or through an integration platform if you want to automate the flow.

Prompt design and business rules are usually owned by Sales/RevOps with support from an AI-savvy engineer. Reruption often helps teams establish these roles, define the first workflows, and then hand over a setup that your internal team can maintain and extend.

For many organisations, the first tangible results come within 2–4 weeks. In the first days, you can already run one-off experiments: upload a CSV, let Claude clean and segment it, and compare it to your current process. That alone can save hours on the next campaign.

Building a more robust, semi-automated workflow—where Claude consistently prepares lists for a specific segment—typically takes a few additional weeks to design, test, and harden. Within one quarter, most teams can move from experimental usage to relying on Claude-powered list building as a standard part of their sales operations.

The direct usage cost of Claude (API or SaaS fees) is usually small compared to the value of the sales time and opportunity cost it saves. The bigger investments are in designing good workflows and integrating Claude into your stack, which is mostly one-time effort plus incremental improvements.

On ROI, companies commonly see reductions of 50–80% in list preparation time, fewer bounced emails, and higher conversion from outreach to meeting. If you have several sales reps or SDRs spending hours per week on list work, the payback period for a Claude-based workflow is often measured in weeks, not years—especially once you scale it across multiple segments and regions.

Reruption works as a Co-Preneur alongside your sales and ops teams. We don’t just hand over slides—we embed ourselves to design and ship working AI workflows. With our AI PoC offering (9,900€), we can validate within a short timeframe whether Claude can reliably clean, segment, and enrich your specific CRM data, and deliver a functioning prototype that your team can test on real campaigns.

From there, we help you turn the PoC into a robust capability: refining prompts and business rules, integrating with your CRM and outreach tools, setting up governance and security, and enabling your teams to operate the solution. The goal is that you end up with a Claude-powered list-building system that lives inside your organisation and replaces the old manual processes—not another external dependency.

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