Gift Card Platform
Issuance and redemption for commerce clients — where a double-spent card is real money lost.
- 10K+ txns/day
- idempotent redemption
- in production
Read the case study
Sagar Gondage
Senior Software Engineer building payment systems that serve 50K+ users daily at Pine Labs.
Systems should be boring in production and interesting in the design doc.
Open to Senior / SDE-2 roles
Explore the console
A live session into how I build — 30 commands, real production numbers. Type help to begin.
sagar@payments-prod — guest session⏱ 00:00
╔══════════════════════════════════════╗
║ sagarOS v2.0.26 — Boot Sequence ║
╚══════════════════════════════════════╝
Initializing sagarOS kernel… [OK]
Mounting payment adapters… [OK]
Verifying idempotency guarantees… [OK]
Reconciling gift-card ledger… [OK]
Loading RBAC policy engine… [OK]
Warming cache hot paths… [OK]
Calibrating rate limiter… [OK]
Loading on-call rotation (n=5)… [OK]
All systems nominal. Integrity: 100%
Welcome to sagarOS v2.0.26
Type 'help' to begin.
START HERE help · whoami · skills · experience
GO DEEPER ls work · cat work/payments-scale.md · status · metrics
FOR FUN coffee · fortune · neofetch · sudo · hack
sagar@prod:~$
production30 commands
50K+
daily active users served
99.9%
production uptime
10K+
transactions per day
5
engineers led
Numbers from production systems I architected and ran at Pine Labs across banking, airlines, travel & e-commerce.
Featured work
Payments Backend at Scale
One backend serving Banking, Airlines, Travel and E-Commerce — different traffic shapes, same reliability bar.
- 50K+ DAU
- 99.9% uptime
- 50+ B2B clients
Read the case study
RBAC Admin Panel
Role-scoped internal tooling — least privilege without slowing operations down.
- 30% faster admin tasks
- least-privilege
- audit-ready
Read the case study
Experience
Senior Software Engineer @ Pine Labs
Nov 2022 — Present · Bengaluru, India
- Led a cross-functional team of 5 engineers across Banking, Airlines, Travel and E-Commerce domains — 100% on-time delivery across 10+ production releases
- Architected modular Node.js backend systems serving 50K+ daily active users at 99.9% uptime
- Built a gift card platform processing 10K+ transactions/day and a B2B corporate gifting platform serving 50+ clients
- Designed an RBAC admin panel cutting admin task time by 30%
- Improved dev velocity by 20% and reduced production bugs by 25%; mentored 5 junior developers through 100+ code reviews
Data Analyst @ eClers
Jan 2021 — Jan 2022 · Pune, India
- Conducted data research across LinkedIn, D&B Hoovers and corporate databases — maintained 10K+ contact records with 25% improved accuracy through automated validation
Education
- Masai School — Full Stack Web Development Bootcamp — 1000+ hour intensive (2022)
- B.E. Mechanical Engineering — Sinhgad College, Savitribai Phule Pune University — GPA 8.6/10
Tech stack
Frontend
- JavaScript (ES6+)
- React
- Next.js
- Redux
- Tailwind CSS
- Material-UI
- Bootstrap
- HTML & CSS
Backend & Data
- Node.js
- Express
- MongoDB
- Prisma
- REST API design
- JWT / OAuth
- Query optimization
Practices & Tools
- Git
- Code review
- Agile / Scrum
- Performance optimization
- Modular architecture
- Postman
- Vercel
Notes
Short technical write-ups from running payment systems in production.
Keeping 99.9% uptime on a payments backend
Timeouts, retries with jitter, idempotency keys — the boring patterns that keep money systems up.
July 2026 · 6 min read
RBAC that survives the org chart
Designing permissions that outlive the roles they were written for.
July 2026 · 5 min read
Let's build something reliable.
Open to Senior / SDE-2 conversations — the fastest way to reach me is email.