Santusht Kotai — Software Engineer & Systems Architect
Living between terminal windows, lofi beats, and real-world wonder — crafting things that work silently so life can happen loudly.
Software Engineer | Backend Engineering | Distributed Systems · Indore, India
Experience
47 Billion — Backend Engineer Intern, COE
Dec 2025 – April 2026 · Indore, India
- Built and maintained 25+ production REST APIs using FastAPI, PostgreSQL, and SQLAlchemy across five enterprise modules, serving 10,000+ daily API requests with consistently low response latency.
- Developed and deployed backend microservices on AWS using cloud-native design principles, supporting scalable workloads and automated deployment pipelines.
Sharexpress Foundation — Founder & Lead Engineer
Jan 2026 – Present · Indore, India / Remote
- Founded an open-source software organization focused on developer infrastructure, distributed systems, and AI-powered platforms.
- Lead system architecture, technical roadmap, engineering standards, and end-to-end development across multiple open-source products including Sharexpress Mail and Interleet.
Featured Systems Projects
Sharexpress Mail Infrastructure & Cloud Services
Jan 2026 – June 2026 · github.com/santusht06/sharexpress
- Engineered a self-hosted mail platform from scratch, implementing core mail services using SMTP, IMAP, and POP3 protocols with 30+ REST APIs, RBAC, Redis caching, and an event-driven backend architecture for scalable mail delivery and user management.
- Designed and deployed the complete infrastructure stack, including containerized services, reverse proxy, service orchestration, background workers, secure authentication, and persistent storage.
Stack: FastAPI, React, Redux Toolkit, Cockroach DB, SMTP, IMAP, POP3, Docker, Nginx, Kubernetes, Minio
Interleet – AI Interview, Coding & System Design Platform
April 2026 – Present · github.com/santusht06/interleet
- Engineered a distributed AI assessment platform for mock interviews, coding challenges, and system design, featuring multi-provider LLM orchestration, secure authentication, and 35+ REST APIs to deliver scalable, real-time technical assessments.
- Built a secure code execution and evaluation engine using non-root Docker sandboxes, AST-based analysis, differential testing, mutation testing, and Redis-backed asynchronous processing to safely execute and accurately validate untrusted code.
Stack: FastAPI, MongoDB, Redis, LangChain, React 19, Redux Toolkit, Docker, WebSockets, AWS
Leadership & Achievements
- Google Summer of Code 2026 (GSoC) (Selected Contributor, Supabase): Selected as an active contributor for Supabase, engineering distributed infrastructure and developer tooling.
- Buildverse Education Technology Hackathon (Winner 2026, Buildverse): Won first prize for architecting scalable AI assessment and real-time distributed learning infrastructure.
- LeetCode Knight (Top 1.2% Globally, LeetCode): Ranked among the Top 1.2% globally with 500+ problems solved across Data Structures & Algorithms, including Graphs, Dynamic Programming, Trees, and Advanced Algorithms.
- Cisco Certified Professional (Certified, Cisco Networking Academy): Certified in Introduction to Modern AI, Python Essentials 1 and 2, Introduction to Cybersecurity, and Introduction to Networks.
- Open Source Contributor (Active, Global Ecosystem): Contributed code and improvements to React, Supabase, Vite, FastAPI, and Linux.
Latest Engineering Notes
- Building a Self-Hosted Mail Server from Scratch (SMTP, IMAP & POP3) — Implementing RFC 5321, RFC 3501, and RFC 1939 from raw TCP sockets with CockroachDB storage and deliverability compliance. (February 27, 2026, 10 min read; Infrastructure, Distributed Systems)
- ADR-001: Why Kafka Was the Wrong Choice for My Architecture — Evaluating distributed append-only logs vs message brokers: Why I rejected Kafka in favor of native Redis Streams. (March 04, 2026, 8 min read; Distributed Systems, Backend, Incidents & ADRs)
- Incident #002: When a 4GB Node Suffocated Under Concurrent Contest Traffic — Post-mortem of a 14-minute production outage during a university coding contest: swap thrashing, kernel OOM cascades, and architectural recovery. (February 20, 2026, 7 min read; Infrastructure, Incidents & ADRs)
- Designing Non-Root Sandboxes for Untrusted Code Execution — Defense-in-depth isolation for online code evaluation: AST parsing, cgroups v2, and seccomp-bpf syscall filters. (February 14, 2026, 9 min read; Security, Infrastructure)
Frequently Asked Questions
- What engineering services and expertise do you offer?
- I specialize in backend engineering, distributed systems architecture, high-throughput REST APIs with FastAPI & Go, database design & indexing with PostgreSQL and Redis, and containerized cloud infrastructure on AWS and Kubernetes.
- How do you approach system design and architecture?
- I follow clean, modular, and fault-tolerant architectural principles. Every system is engineered with clear service boundaries, atomic transactions, connection pooling, and resilient failover mechanisms.
- What core technologies and tech stack do you work with?
- My primary backend stack includes Python (FastAPI, SQLAlchemy), Golang (Gin), PostgreSQL, Redis, Docker, Kubernetes, AWS, and Cloudflare Workers. On frontend, I work with React, Vite, and Redux Toolkit.
- What open-source and distributed systems projects have you built?
- I am the founder of Sharexpress Foundation, creator of Sharexpress Mail (self-hosted SMTP/IMAP/POP3 mail infrastructure), Interleet (distributed AI coding sandbox), and an active contributor to Supabase (GSoC 2026).
- Can you collaborate on existing codebases or microservices?
- Yes, I regularly integrate into existing enterprise architectures, optimize database query performance, remediate OWASP vulnerabilities, and scale high-throughput API endpoints.
- How can I contact you or collaborate on engineering projects?
- You can reach out directly through the contact form on this site, or via email at [email protected], GitHub (github.com/santusht06), and LinkedIn.
Read all engineering articles · See all work and projects