SPEND ANALYZER: Orchestrator API
[002] Business Problem
Deepening the customer relationship through data — Understanding customer spending habits in greater depth lets Capital One build stronger, longer-term relationships with customers. With a fuller picture of a customer's spending, the bank can better match customers to products that fit their lifestyle and financial needs, rather than offering generic products.
[003] My Role
I served as tech lead on the Spend Analyzer Orchestrator API, leading a team of two senior engineers to design and build the orchestration layer — the backend layer that sits between the mobile front end and the heavier backend data layers, translating raw data into what the front end actually needed across three separate endpoints.
Each endpoint carried its own web of dependencies across stakeholders, which meant I had to have a thorough understanding of the customer experience and user flow before any API design decisions could be made. I took a design-forward approach, working closely with Product, Frontend, and Data teams to align on architectural design before diving into technical trade-offs and decisions.
With three engineers building in parallel, I also drove standardization across the codebase — abstracting repetitive logic into shared libraries and setting a coding standard the whole orchestration layer followed so the code stayed clean and scalable. The implementation was delivered ahead of schedule and fully tested, ready for the upcoming high-visibility launch and customer rollout on the "Pay and Move" tab (coming September 2026), which will reach all mobile app credit card users.
[004] Approach
Context
The Orchestrator API had to solve two problems at once: turning raw, high-volume transaction data into something the front end could display quickly and cleanly, and handling real customer financial data with the legal and compliance weight that comes with it. Getting either wrong — a slow experience, or the wrong data reaching the wrong person — posed a real risk to the product's credibility from day one.
One Source of Truth
With three engineers building three endpoints in parallel, several pieces of logic — including the role-based access rules, spend visualization/graphing logic, and rounding on aggregated totals — needed to behave identically across all of them. Rather than let each endpoint implement its own version, I abstracted these into shared, universally accessible components. Any future change to one of these business rules now only needs to happen in one place, rather than being tracked down and updated separately across three endpoints.
Testing Against Every Number
Testing went beyond confirming the feature worked end to end. I structured testing calls with defined roles and clear accountability across every stakeholder — tech and product together defined a universal set of test transaction scenarios up front, and built test accounts that mimicked each one. Live trackers held the expected result for every scenario, defined ahead of time, so validation could be checked directly against them. That validation went down to the individual rounding dollar on aggregated totals, confirming the entire experience stayed consistent and accurate, not just functionally correct.
Designing for Legal Accountability
Financial data carries real legal weight around who is allowed to see what. Primary account holders can see all transactions on the account; Authorized Users can only see their own. I owned the technical design and implementation of that rule across all three endpoints, along with the testing needed to confirm it held consistently everywhere the API surfaced data.
[005] Results
Spend Analyzer shipped to production and is set to become available to customers, giving them a way to track and understand their spending — pulling from two years of posted transaction history across 17 categories and the full range of merchants. Spending is grouped by merchant and category and visualized in a way that makes it easy to compare current spending against the previous year, reaching all Capital One mobile app credit card users on the "Pay and Move" tab in September 2026 [screenshots will be added in Sept'26 when the feature is available to the public].
The Orchestrator API made this possible by reconciling what the front end needed to display with the data actually available on the backend, bringing that structured, grouped spending data together into a clean format customers can understand at a glance.
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