Frontend Platform Engineering · Fintech
Senior Software Engineer at BILL with 7 years building the systems behind fintech products used by hundreds of thousands of SMBs.
Current focus at BILLLeading the vendor onboarding overhaul
Selected work / 01
Career progression across fintech platforms, product engineering, and scalable frontend systems.
Full-time · Jun 2024 - Present
Promoted to Senior Software Engineer with expanded team scope across Accounts Receivable and vendor onboarding.
Full-time · Jul 2021 - Mar 2024
Led reusable SDK and UI platform components for high-volume fintech payment workflows.
Software Engineer Intern
Shipped iOS 14 widgets for the flagship app and built serverless incident tooling (AWS Lambda, Terraform) that cut operational costs by ~10%.
Software Engineer
Built AWS S3 content delivery and adaptive video streaming for an edtech platform, lifting daily active engagement ~20%, and mentored junior engineers.
Application Engineer
Summer internship: production debugging and JIRA-driven issue analysis with data-backed UX recommendations.
A map of how I connect product surfaces, platform foundations, and delivery systems.
From customer experience to delivery
Product flows that turn complex AR, billing, and payment operations into clear customer-facing experiences.
Core stack
Proof points
Composable frontend surfaces that let product teams ship independently while keeping shared platform quality.
Core stack
Proof points
Reusable UI and SDK foundations that reduce repeated implementation work across fintech integrations.
Core stack
Proof points
Clear frontend-backend contracts that make data fetching predictable, efficient, and easier to evolve.
Core stack
Proof points
Automated validation systems that protect release confidence across shared product and platform workflows.
Core stack
Proof points
Operational guardrails that make large frontend surfaces safer to release, debug, and improve.
Core stack
Proof points
Developer workflows that use automation and AI-assisted engineering to move faster without losing accuracy.
Core stack
Proof points
Patterns I have shipped, written to be reused. The structure, the cost, and when to reach for something else.
Split a frontend along ownership and deploy cadence, not along technical layers or page routes. The boundary is right when a team can ship its surface without coordinating with anyone else.
Platform DesignTreat the schema as a published contract with named owners and a deprecation policy, not as a type file any team may extend. Federation distributes authorship, which makes ownership the thing that has to be designed.
SDK ArchitectureShip an SDK as two layers: a headless core carrying logic, state, and API contracts, and a UI layer built on top of it. Clients take both or take only the core, without either path being second class.
Master of Science in Software Engineering with a 3.97 / 4.0 GPA.
Bachelor of Technology in Information Technology.
Grouped around the systems I build and maintain.
Platform Engineering
Select a cluster to explore
Product surfaces, design systems, and modern frontend stacks.
Related work
Shared platform patterns for scalable product delivery.
Related work
Automation, observability, quality gates, and release confidence.
Related work
Service foundations and data layers that support product workflows.
Related work
Feature delivery habits that connect engineering choices to outcomes.
Related work
Select a cluster to explore
Products I'm actively developing outside of work.
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Pattern-first study
Explore trigger signals, invariants, and examples behind common DSA techniques.
Recall before reveal
Reconstruct the reasoning, compare it with the explanation, and rate your recall.
Connected practice
Move between pattern guides and practice problems, tracking what you’ve studied and solved.
Progress that stays local
Keep notes, bookmarks, and review history in your browser, with exportable backups.
Technology
Pattern-first study
Explore trigger signals, invariants, and examples behind common DSA techniques.
Recall before reveal
Reconstruct the reasoning, compare it with the explanation, and rate your recall.
Connected practice
Move between pattern guides and practice problems, tracking what you’ve studied and solved.
Progress that stays local
Keep notes, bookmarks, and review history in your browser, with exportable backups.
Technology
A privacy-first PDF toolkit that processes documents locally in the browser. Ten focused tools cover everyday PDF work without uploading document content to a server.
Local by default
Document bytes stay in the browser with no file-upload endpoint.
Complete page toolkit
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Convert images and PDFs, then add watermarks or page numbers.
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Technology
Local by default
Document bytes stay in the browser with no file-upload endpoint.
Complete page toolkit
Merge, split, rotate, extract, and remove PDF pages in one workspace.
Conversion and finishing
Convert images and PDFs, then add watermarks or page numbers.
Fill and sign
Complete forms and add signatures without sending documents away.
Technology
Interactive study tool for Senior Frontend interviews
58 topics · 13 categories
Full senior frontend interview spectrum: JS, TS, CSS, React Core, Patterns, State, Testing, Performance, and more.
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Progress tracking
Mark-as-complete system with localStorage persistence. Your progress survives page refreshes.
Stack
58 topics · 13 categories
Full senior frontend interview spectrum: JS, TS, CSS, React Core, Patterns, State, Testing, Performance, and more.
Live Sandpack editor
Each topic ships a pre-loaded code sandbox. Edit in-browser and see results instantly with no setup.
React Flow DAG roadmap
Visual dependency graph of all topics. Hover for tooltips, click to jump. See what to learn in what order.
Progress tracking
Mark-as-complete system with localStorage persistence. Your progress survives page refreshes.
Stack
Real problems, real constraints, and the platform decisions behind them.
BILL
Shipped Bulk Mark as Paid, Recurring Invoices, Scheduling, Payment Links, and invoice customization, expanding AR capabilities for the full customer base. Measurably improved frontend performance, test coverage, and engineering velocity across critical workflows.
Problem: BILL's Accounts Receivable platform was built on a legacy monolithic frontend. Slow to ship, difficult to test, and increasingly misaligned with the scale demands of hundreds of thousands of SMB customers.
Approach: Led modernization of core AR workflows into scalable microfrontend experiences. Integrated GraphQL-driven data fetching, rationalized LaunchDarkly feature flags, standardized Playwright automation patterns, and drove cross-functional alignment across product, backend, and platform teams.
Jun 2024 to Present
BILL
Problem
BILL's Accounts Receivable platform was built on a legacy monolithic frontend. Slow to ship, difficult to test, and increasingly misaligned with the scale demands of hundreds of thousands of SMB customers.
Approach
Led modernization of core AR workflows into scalable microfrontend experiences. Integrated GraphQL-driven data fetching, rationalized LaunchDarkly feature flags, standardized Playwright automation patterns, and drove cross-functional alignment across product, backend, and platform teams.
Result
Shipped Bulk Mark as Paid, Recurring Invoices, Scheduling, Payment Links, and invoice customization, expanding AR capabilities for the full customer base. Measurably improved frontend performance, test coverage, and engineering velocity across critical workflows.
BillGo
Reduced downstream integration effort by approximately 90% across multiple client implementations. Cut end-to-end testing time by 50%. Delivered a platform that let new clients go from zero to integrated in days instead of months.
Problem: Every new fintech client integration required bespoke frontend work from scratch. Duplicated effort, inconsistent quality, and multi-month timelines that blocked commercial growth.
Approach: Architected a cross-platform SDK with a clean headless/UI library split, giving clients flexibility without sacrificing consistency. Built native iOS and Android reference apps to validate the architecture, implemented Detox-based automation, and set up GitHub Actions pipelines for continuous delivery.
Jul 2021 to Mar 2024
BillGo
Problem
Every new fintech client integration required bespoke frontend work from scratch. Duplicated effort, inconsistent quality, and multi-month timelines that blocked commercial growth.
Approach
Architected a cross-platform SDK with a clean headless/UI library split, giving clients flexibility without sacrificing consistency. Built native iOS and Android reference apps to validate the architecture, implemented Detox-based automation, and set up GitHub Actions pipelines for continuous delivery.
Result
Reduced downstream integration effort by approximately 90% across multiple client implementations. Cut end-to-end testing time by 50%. Delivered a platform that let new clients go from zero to integrated in days instead of months.
Notes on platform-scale frontend. What worked, what surprised me, and what I'd do differently.
Angular is opinionated about where files go and silent about what is allowed to depend on what. Teams keep mistaking the first for the second, and end up with codebases that look organized and behave like a tangle.
A test suite's job is not to prove your code works. It is to give you permission to change it. Most suites are optimized for the first goal and quietly make the second one harder.
Every fintech frontend eventually renders a balance as if it were settled fact. It almost never is. The bugs that follow are not arithmetic bugs, they are modeling bugs wearing arithmetic as a disguise.
Three days, forty comments about naming and imports, and nothing about whether the change should exist. Most code review is theater. The best reviewers are doing a different job entirely.
The monorepo vs polyrepo debate resurfaces every few months, and it is almost never about repo structure. Slow CI, unclear ownership, and under-funded tooling wear the repo as a costume.
Up next
Human review is the standard answer to "what if the model is wrong." Most review queues are built in a way that guarantees approval, which produces the appearance of oversight and none of the substance.
The writing archive
Explore the complete collection on frontend architecture, platform engineering, and engineering craft.
What managers and peers I've shipped with say.
Manager endorsement
Ben McKinley
Software Engineering leadership
Direct manager at BILL · June 2026
“Anshul is a strong engineer who does not wait to be told what to own.”
Excerpt from Ben's recommendation
Josh Foeh
Staff Software Engineer at BILL
Senior peer at BILL
“I've been consistently impressed by his ability to understand exactly what needs to be built and then to build it at lightning speed. His questions are thoughtful and show that he approaches problems from a holistic perspective rather than just trying to close a ticket.”
Becca Moss
Staff Software Engineer at BILL
Senior peer at BILL
“Anshul combines strong engineering skills with a genuine commitment to our customers. His customer-first mindset makes him a trusted partner across the organization. He is an outstanding teammate, thoughtful, collaborative, and always willing to help others succeed.”