Skip to content
Doc · SB / Portfolio · Rev 10.26
Role · Software Development Engineer
Now · Fidelity Investments · Plynk
Base · Bengaluru, India

Swayam Bajpai

I build the money-moving back ends and the screens in front of them: Spring Boot microservices and an Angular app at Fidelity, and before that a whole edtech platform shipped to Google Play.

  • 9 codebases at Fidelity
  • 7 back-office calls → 1 parallel request
  • HTTP 207 partial success
  • 14 Play Store builds
  • 0% → 100% exam saves
  • Terraform blue/green on AWS EKS
  • WCAG 2.2 · 3 languages
  • Kafka · gRPC · SQS · WebSockets · WebRTC
  • 41 projects · 21 case studies

§01 · Experience · 2024 → now

Where I've shipped

Plynk Invest · FCAT

Fidelity Investments

Software Development Engineer

Sep 2025 — Present · Bengaluru

Plynk is Fidelity's mobile-first investing app for new investors. I work across the ground-up Angular rebuild of the app and the Java / Spring Boot microservices behind it, deployed with Terraform blue/green on AWS EKS across 4 environments and 2 regions.

  • 9codebases I've shipped in
  • 13merged PRs in the app rebuild
  • 34versioned BFF endpoints
  • 3languages: EN · ES · FR-CA

System map

Select a system · 9 codebases

S/01 · Mobile app

Plynk mobile app rebuild

A ground-up Angular rebuild of the Plynk app for iOS, Android and web, in an Nx monorepo with 60+ libraries.

What I built

  • Brokerage & IRA account opening: 20+ lazy-loaded wizard steps, so each screen downloads only its own code
  • SSN masking, US-only address autocomplete (3-char minimum, debounce + switchMap) and validation in 3 languages
  • WCAG 2.2: keyboard access, screen-reader validation, iOS/Android safe areas, enforced by Playwright accessibility audits
  • Real-time WebSocket quotes with per-symbol signals and a 10 s debounced unsubscribe when a tab is backgrounded
  • linkedSignal() refactor that fixed a stale selection bug in the real-time-quotes modal; exhaustMap guards against double-submitted orders
  • Angular
  • Signals
  • NgRx Signal Store
  • Nx
  • Jest
  • Playwright
Delivery →Contract-first: 19 OpenAPI specs generating modelsJenkins with SonarQube, CodeQL and Veracode gatesTerraform blue/green on AWS EKS, 2–5 pod autoscalingHardened non-root containersDatadog APM and Micrometer, with PII scrubbing on every log

Merchant Navy exam prep

Marine Edge

Software Development Engineer

Mar 2024 — Aug 2025 · Bengaluru

An edtech platform for Merchant Navy aspirants (GP Rating, IMU-CET) with 4 portals: public tools, student, tutor and admin/superadmin. In a three-person team I built the Angular Android app end to end, and the public tools, student and staff portals and checkout on the Next.js web platform.

  • 140+web routes
  • 49mobile screens
  • 14Play Store builds
  • 2,500+mobile unit tests

System map

Select a system · 9 areas of the platform

S/01 · Mobile app

Android app

The student app on Google Play, built with Angular, Ionic and Capacitor: courses, recorded and live classes, tests and payments.

What I built

  • 49 screens and 13 NgRx stores, covered by 167 spec files (2,500+ unit tests)
  • Onboarding, signup and OTP login flows, with auth state that no longer bleeds between users and clear messages for duplicate accounts
  • Exam and quiz screens, and the live-class UI
  • Fixed a native-bridge bug where 18-digit attempt IDs lost precision as JS numbers: exam saves went from 0% to 100%
  • Fixed a 401 → login → 401 redirect loop that blanked the app on startup
  • Angular
  • Ionic
  • Capacitor
  • NgRx
  • Jasmine
  • Karma
Delivery →Separate testing and production Android buildsGoogle Play target SDK 36Vitest on the web, Jasmine/Karma on mobile

Education · 2021 — 2025

BMS Institute of Technology and Management

B.E. Information Science and Engineering

Data Structures & Algorithms · Operating Systems · DBMS · Computer Networks · OOP

Certifications

  • Architecting Solutions on AWS (Amazon Web Services)
  • Tools of the Trade: Linux and SQL (Google)
  • Linux Commands & Shell Scripting (IBM)

§02 · Problems from production

Field notes

N°1

Fidelity · Spring Boot

Latency of the slowest call, not the sum of seven

Problem
The account dashboard needed data from 7 back-office systems: balances, positions, performance, IRA, crypto and more. Calling them one after another adds every latency together.
Fix
Fan out with CompletableFuture on a bounded executor, give each call its own timeout, and merge results as they arrive. A failed system becomes a missing section instead of an error page.
Outcome
Dashboard latency is bounded by the slowest dependency, and one system going down no longer takes the dashboard with it.
N°2

Fidelity · Accounts BFF

HTTP 207 for batches that half-succeed

Problem
Batch requests across accounts failed as a whole if a single item failed, which forced clients to retry work that had already succeeded.
Fix
Batch endpoints return 207 Multi-Status with a per-item status and error. The client retries only what failed. Versioned contracts (v1/v2/v3) keep older app builds working.
Outcome
No more all-or-nothing batches, and no breaking changes for app versions already in users' hands.
N°3

Marine Edge · Mobile

0 of 49 exam IDs survived the native bridge

Problem
Exam answers silently failed to save on the mobile app. Every attempt ID coming back from the backend pointed at the wrong record.
Fix
Traced it to 18-digit IDs passing through a JavaScript number, which loses precision past 2⁵³. I kept IDs as strings end to end across the bridge and the API layer.
Outcome
Exam answer saves went from 0% to 100%.
N°4

Marine Edge · Mobile

Lecture progress without flooding the API

Problem
The lecture player reported progress constantly, and the app decided on its own when a lecture was complete, so phone and web could disagree.
Fix
The Android player now saves only when progress moves 5% or more, or when it crosses 90%. Completion comes from the server's response instead of a local comparison, so every device shows the same state.
Outcome
Far fewer progress writes, and the same completion state on phone and web.

§03 · 41 projects · 21 case studies

The work index

Case studies

Architecture, decisions, trade-offs

Everything I've built

github.com/swayam555

§04 · 40 elements · each one used in real work

Periodic table of my stack

1LAJv

Language

Java

Used in · Fidelity services · Veil · Foyer · FraudShield · MediSync

Select an element to see where it was used

§05 · Open to SDE roles · back end / full-stack

Let's talk

Call or message me on WhatsApp. It's the fastest way to reach me. Email works too, and I reply within a day.

+91 87077 05446
Scan → WhatsApp+91 87077 05446
Open WhatsApp chat

Based in Bengaluru, India · IST (UTC+5:30)