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MOHIT KAREKAR
Berlin, DE | karekar.mohit@gmail.com | LinkedIn | GitHub | mohitkarekar.com
SUMMARY
Software engineer with 8 years of experience in building reliable web platforms, developer tooling and managing web infrastructure. Proficient in TypeScript, Node.js, React, Go, and building and maintaining large-scale web services and developer tooling. Strong background in observability platforms (w/ OpenTelemetry), cloud infrastructure (Kubernetes, AWS, databases, performance/load testing) and on-call incident response.
WORK EXPERIENCE
Zalando SE, Berlin, Germany October 2021 - Present
Principal Software Engineer (May 2025 - Present)
Senior Software Engineer (October 2021 - April 2025)
- Organisation-wide Load Testing: Led and drove load testing efforts in 2023 & 24 in preparation for Cyber Week (high-traffic event). Managed contributions from and collaborated with over 30 engineers, conducted over 10 successful load tests (250K+ RPS) each year. In 2024 designed and led the adoption of OSS Grafana k6 tooling (Go Kubernetes operator, test framework, contribution model) by leading a team of 4 engineers. Extended to offer it as a service in the organisation for self-serviced load testing.
- Critical E2E Tests Management & Execution: Designed a solution to manage and execute critical user journeys as automated tests to monitor the availability of key business use cases - leading to an increase of 30% of critical test coverage. Built on-demand test execution infrastructure supporting Playwright & Appium-based tests.
- Operations & Maintenance of central web framework: Developed and evolved internal framework “Rendering Engine” and supported over 100+ daily users of internal web framework (built on top of Node.js and React). Added APIs for experimentation and observability to the framework. Maintained and participated in on-call shifts for infrastructure deployed in Kubernetes on AWS with a steady traffic of ~7K RPS, led performance optimizations.
- Client-side observability: Core contributor of internal JavaScript observability SDKs based on OpenTelemetry. The SDKs provide observability to over 90 Node.js & browser apps at Zalando. Designed and implemented mobile-native performance metrics to be tracked in React Native. [blog post]
- Local DevEx & Tooling: Designed surveys and interviews (>10 eng.) to gather information on shortcomings with local developer experience. Built developer tools and environments in Go used by over 100 engineers for local development, improving iteration speed and reducing context-switching.
- Automated Deployments and Continuous Regression Monitoring: Implemented a monitoring service to observe new deployments, catch regressions and alert engineers or rollback for a distributed monolith. Cut down 2 hours of daily manual effort per engineer, increased the number of deployments to 4/day. Implemented multi-window alerts for reduced noise and improved alert quality.
- Image Performance Optimization: Built tooling to catch anomalies w.r.t. incorrect images used on the website. The tooling detected images greater than the required size, density and checked for other web performance-related best practices, and caught performance regressions in production.
- Technical Interviewing & Mentoring: Conducted regular technical interviews (a mix of general tech and system design) for senior and non-senior positions. Mentored 2 junior engineers entering into web development.
upGrad, Mumbai, India April 2019 - September 2021
Senior Software Engineer (April 2021 - September 2021)
Software Engineer II (April 2019 - March 2021)
- Web Performance: Led performance optimization of upgrad.com, improved Lighthouse scores by 300% on desktop & mobile.
- accounts.upgrad.com: Led the growth frontend team for the project to unify user authentication, created a shared library of components encapsulating state-machines of authentication logic to be used across platforms.
- Internationalization: Scaled the platform to handle seamless platform scalability across 10+ countries and regions with fallback mechanisms. Included CMS & infrastructure level optimizations.
- In-house CMS: Built a CMS frontend from scratch enabling content edits. Solved problems like building an authentication layer, live previewing, data replication across environments, and task queues for process-heavy tasks. Brought down the effort of building a page from 1 week to 2 hours.
- Marketing Platform: Owned upGrad’s marketing platform built in Nuxt.js (server-side rendered) with a modular architecture and supported by a Node.js CMS. Worked on features like dynamic form rendering, optimizing page load speed, and building UI components. Handled AWS services like CloudFront, Lambda and S3. Deployed on EKS.
Terribly Tiny Tales, Software Engineer, Mumbai, India May 2018 - April 2019
- Tribe: Built an end-to-end writer submission platform that included a cross-platform mobile app in React Native, a Node.js backend, and an admin dashboard written in React.
- Social App: A social networking platform built by TTT for writers. Contributed to the admin dashboard and backend APIs. Worked on feed generation algorithms affecting a network of over 100K users.
TECHNICAL SKILLS
- Programming Languages: TypeScript, Go, C++
- Tools & Platforms: Node.js, React, Kubernetes, Docker, Postgres, Amazon DynamoDB, Redis, OpenTelemetry, Amazon Web Services (AWS), Grafana k6, ServiceNow Cloud Observability, Prometheus, Skipper
- Skills: Web Platform, Site Reliability Engineering, Load Testing, Observability, Developer Experience & Tooling, JavaScript tooling and compilers
- Others: Technical Interviewing, Part of SRE Champions program internally (supporting embedded SRE expertise)
EDUCATION
Georgia Institute of Technology, Atlanta, Georgia (Part-time, Online) 2021 - Expected Graduation in 2026
- MS in Computer Science, Specializing in Computing Systems
- Relevant Coursework: Software Analysis & Testing, Computer Networks, Compilers: Theory and Practice, Graduate Introduction to Operating Systems, Advanced Operating Systems, Database Systems Impl.
Visvesvaraya National Institute of Technology, Nagpur, India 2013 - 2017
- B.Tech. in Electrical & Electronics Engineering
- Thesis: Optimization using metaheuristic algorithms in electrical systems
INTERESTS
- Distributed Systems: Organiser of an internal paper reading guild where we present and discuss distributed systems papers.
- Compilers: Implemented a compiler for a toy language Gom and working on a compiler-writing series.