Harsh Singh

Summary

I'm an open source engineer specialising in numerical time integration and solver internals. I have 240+ merged pull requests to projects maintained by others, including 151 in the SciML organisation and 111 in OrdinaryDiffEq.jl. NumFOCUS and SciML fund my work through Google Summer of Code 2026 and the SciML Small Grants Program, and I do research with TU Hamburg on spectral deferred correction and with Oxford's Numerical Analysis Group on Irksome. Away from scientific computing I ship production TypeScript and Go: ScrollCraft, launched as a SaaS in the Sarvam Startup Program and since made open source; Kitbash, a CLI on npm and Homebrew; and merged contributions to three CNCF organisations.

Experience

1. May 2026 - Present

   Open Source Developer (Google Summer of Code 2026)

   NumFOCUS - SciML · Remote

   • Develop and maintain numerical ODE, SDE, DAE and DDE solvers in Julia for the SciML organisation, mentored by Chris Rackauckas.
   • Implemented the MRI-GARK multirate infinitesimal families plus MIS2, MRAB, MREEF and MREIL, and the IMEX SDIRK/ESDIRK schemes with a generic tableau abstraction shared across the family.
   • Identified and corrected an error in a published multirate order condition, caught by convergence order tests with negative controls.
   • Built modified Newton nonlinear solves on the DAE paths with W operator construction and reuse.
   • Shipped after the program period: the spectral deferred correction family (nine sweepers and adaptive step control, with IMEX sweeps in review) and PETScDiffEq.jl, a new SciML package wrapping PETSc's TS solvers with discrete adjoint support, now at v0.3.0.
2. Aug 2026 - Present

   Research Collaboration

   TU Hamburg - Chair of Computational Mathematics · Remote

   • Bringing Spectral Deferred Correction into OrdinaryDiffEq.jl with Daniel Ruprecht's group, working toward a joint publication.
   • Delivered serial SDC with seven sweepers, verified against the qmat reference implementation, with stiff coverage on Prothero-Robinson.
3. Sep 2026 - Jun 2027

   Research Intern

   University of Oxford - Numerical Analysis Group · Remote

   • Working with Professor Patrick Farrell's group and Dr Pablo Brubeck on Irksome, the Runge-Kutta time stepping library for finite element problems in Firedrake.
   • Reported six defects in the stepper implementations, including transposed abscissae in a published tableau and stage residuals evaluated at the wrong time.
4. 2026

   Funded Contributor

   SciML Small Grants Program (NumFOCUS) · Remote

   • Awarded and completed a funded project adding eight differential algebraic equation benchmarks from the Bari IVP test set to SciMLBenchmarks.jl, across mass matrix, residual DAE and ModelingToolkit index reduced formulations.
5. Jun 2025 - Sep 2025

   React Developer Intern

   Krtya Technologies Pvt. Ltd. · Remote

   • Built responsive React interfaces against REST APIs and improved frontend rendering performance.

Selected projects

• 2026

  ScrollCraftSaaS · Sarvam Startup Program

  An AI scroll-animation site builder I launched as a paid SaaS, then made free and open source.

• 2026

  Amazon ML Challenge 2026Competition · team Inno8

  Business entity resolution across 10 million noisy multilingual records: 0.988642 public F0.5 among 8,269 teams.

• 2026

  impact-adjointTesseract Hackathon 2026

  Exact gradients through impact events, computed in Julia and served into a single jax.grad.

• 2026

  PETScDiffEq.jlNew SciML package · author and maintainer

  PETSc's time integrators behind the SciML solve interface. I wrote it and maintain it.

• 2026 - now

  OrdinaryDiffEq.jlOpen source · SciML

  SciML's differential-equation solvers in Julia, and where most of my open source work lives.

• 2026

  KitbashOpen source CLI · npm and Homebrew

  Write an AI agent skill once and compile it for ten coding agents.

• 2026

  Meshery MCP ServerCNCF · LFX Mentorship proof of concept

  A read-only MCP server that lets AI clients query Meshery safely.

• 2026

  DAE benchmarks for SciMLBenchmarks.jlSciML Small Grants Program

  A funded suite of eight index-2 and index-3 DAE benchmarks.

• 2025 - 2026

  CNCF upstream contributionsMeshery, MeshSync, KubeEdge, Kubernetes SIGs

  Concurrency and correctness fixes across three CNCF organisations.

Technical skills

Languages

Julia, Go, TypeScript, JavaScript, C++, Python, Java

Scientific Computing

OrdinaryDiffEq.jl, DifferentialEquations.jl, ModelingToolkit.jl, SciMLBenchmarks.jl, PETSc, Firedrake, Irksome, Numerical time integration, DAE, ODE, SDE and DDE solvers, Automatic differentiation

Cloud Native

Kubernetes, Docker, client-go, Model Context Protocol, GitHub Actions CI/CD

Web and Frameworks

React, Next.js, Node.js, Express, React Native, Flask, Prisma, Tailwind CSS, Auth.js

Data and Infrastructure

PostgreSQL, MySQL, MongoDB, SQLite, Redis, Firebase, Vercel

Testing and Tools

Git, GitHub Actions, Vitest, Jest, Playwright, Postman, Sentry

Education

• Jul 2023 - Jul 2027

  Sarvajanik College of Engineering and Technology, Surat

  Bachelor of Technology, Information Technology · CGPA 9.0 / 10

• Jun 2025 - Aug 2025

  Indian Institute of Technology Madras (remote program)

  Artificial Intelligence and Machine Learning Program