Josh Berns

Software engineer · Founder of Polynode (acquired by agg.market) and MASHBOX Labs

Based in Bangkok, open to relocating US citizen, no visa sponsorship needed

Summary

I fight the speed of light with software: real-time data infrastructure, on-device AI, native iOS apps and AI-built game worlds. I founded Polynode, a real-time Polymarket data API that agg.market acquired in July 2026, and built agg.market’s native app for iPhone, iPad and Mac. I also founded MASHBOX Labs. Self-taught, I went from music photography to smart contracts to shipping products. I contribute regularly to llama.cpp and work every day with parallel AI coding agents (Claude Code, Codex) behind review and verification gates across production systems.

Experience

MASHBOX Labs · Founder

2026 to present
  • Founded MASHBOX Labs to build MASHBOX: one engine that loads the worlds and play styles of games a player owns and mixes them into one game, with multiplayer.
  • Released the Windows app in free early access; MASHBOX’s own worlds run in the browser. mashbox.gg
  • MASHBOX Labs is a member of NVIDIA Inception.

agg.market · Engineer

2026 to present
  • Joined with the acquisition of Polynode and kept working across the product.
  • Built the native agg.market app in Swift and SwiftUI for iPhone, iPad and Mac from one codebase, now in public beta on TestFlight.
  • The app puts every prediction market venue on one screen, with smart order routing that splits each trade for the best price, and live crypto rounds.

Polynode · Founder and engineer

Oct 2025 to Jul 2026 · acquired by agg.market
  • Built Polynode, a real-time Polymarket data API that decodes orders 3 to 5 seconds before they land onchain and streams them over WebSocket and REST.
  • Built a historical archive of 1.2B+ fills across 2.7M wallets and 1M+ markets, queryable through a SQL explorer.
  • Data layer for more than $2B of Polymarket trading volume. Customers include betmoar, Gate, PolyHelper.io, POTS, TerminalUp, standtrade, PolymarketScan.org, Polygun, Polycool and Share.

Mithril · Creator

Sep 2025 to present
  • Built a free iPhone and iPad app that runs LLMs entirely on-device: Apple’s on-device model plus open GGUF models from Hugging Face. Rated 4.5 stars on the App Store.
  • Added memory-fit checks before each download, a live engine dashboard (tokens per second, time to first token, cache) and on-device speech with NVIDIA Parakeet.
  • Gave it agent tools that act with permission through Reminders, Calendar, Messages, Maps and Shortcuts, and a live map of every network request.

Independent products and freelance

2022 to 2025
  • Shipped AI products and sold two of them: DoFDGPT, which turns government contract opportunities into briefs, and SnapCycle, an AI recycling assistant.
  • Quantish let AI agents trade prediction markets and moved about $500K in volume.

Generative photography and AI video

2022 to 2024
  • Produced AI video for an AMC documentary.
  • Trained custom Stable Diffusion models on people and subjects and placed them in scenes with inpainting.

Smart contracts and Camera Person

2021 to 2022
  • Learned smart contract development: wrote and deployed contracts, built the minting sites around them and shipped tools like rarity rankings and sales bots.
  • Built Camera Person, a collective art gallery of 122 photographers from 39 countries, with every sale split equally on-chain.

East Coast music venues · House photographer

2018 to 2021
  • Shot for venues including Franklin Music Hall in Philadelphia and I.M.P.’s venues in Washington, D.C., then for the artists themselves.

Open source contributions

Contributions by Josh Berns / MASHBOX Labs. Full list with links: boshjerns.com/oss

llama.cpp
  • Merged #30737 Exact f32 gelu_quick on CPU, with SIMD.
  • Merged #30736 Qwen-VL image resize that matches transformers.
  • Merged #30108 Exact GELU for ModernBERT encoders.
  • Merged #29692 Configured activation for reranker heads.
  • Merged #29627 Configured pooling for ModernBERT rerankers.
  • 2 open pull requests
JAX / XLA
  • Confirmed bug xla#51365 Wrong TPU results from a dilated convolution. beckerhe (XLA team): “Indeed, this looks wrong. Thanks for reporting this. I'm working on a fix!” Fix: openxla/xla#51380.
  • 2 open pull requests, 1 bug report
MaxDiffusion
  • 4 open pull requests
Hugging Face
  • 1 open pull request
Kimodo (NVIDIA)
  • 1 open pull request
SocialNavSUB
  • 1 open pull request
PyMeshLab
  • 1 open pull request
Apple Metal
  • 2 bug reports to Apple
Blender
  • 1 open pull request

Selected projects

Technologies

Numbers point to Where I used it. TPU work at MASHBOX Labs is research and engineering, not a public service.

Languages
Rust1 TypeScript2 Python3 Swift4 C and C++5 JavaScript6 Solidity7
Backend frameworks and runtimes
Tokio8 Axum9 NestJS10 Prisma11 Node.js12 Deno (Supabase Edge Functions)13 Bun14
Databases and storage
PostgreSQL15 PgBouncer16 Redis17 SQLite18 PostgREST19
Messaging and streaming
WebSockets20 Apache Kafka21
Infrastructure and cloud
Hetzner22 Cloudflare23 Cloudflare Workers and R224 Cloudflare Pages25 Google Cloud TPU26 Google Cloud Storage27 Amazon Web Services (ECS, MSK)28 Docker29 Caddy30 Linux and systemd31 Supabase32 Pulumi33 Kubernetes34 OpenTofu35
CI/CD and DevOps
GitHub Actions36 Harness37 Playwright38
Observability
Grafana39 Grafana Loki40 PostHog41
Web frontend
React42 Vite43 Tailwind CSS44 Next.js45 three.js46 WebGPU47 WebAssembly48 WebRTC49
Mobile and desktop
SwiftUI50 App Store and TestFlight51 Apple Foundation Models52 React Native and Expo53 Tauri54 NSIS55 WalletConnect (Reown)56
ML and AI
llama.cpp57 JAX58 Pallas59 XLA60 Flax and Optax61 MaxDiffusion62 PyTorch63 Hugging Face Hub64 ONNX Runtime65 NVIDIA Parakeet66 Whisper (ExecuTorch)67 Stable Diffusion68 Claude Code and Codex69 LLM APIs (OpenAI, Anthropic)70 Model Context Protocol71
Game, graphics and 3D
Bevy72 Unreal Engine 573 Blender74 Jolt Physics75
Blockchain and onchain data
Polygon76 Alloy77 viem and ethers78 Chainlink Data Streams79 The Graph (graph-node)80 Envio HyperIndex81 Goldsky82 Hyperliquid83
Payments, auth and SaaS
Stripe84 Mintlify85 Telegram Bot API86 Railway87

Education

Self-taught.

Press

Where I used it

  1. Rust: Polynode's real-time API and orderbook service.
  2. TypeScript: agg.market venue integrations (Betdex, Tip Run, Pred).
  3. Python: Polynode's Python SDK for streaming Polymarket data.
  4. Swift: The native agg.market app for iPhone, iPad and Mac.
  5. C and C++: Reranker and encoder model support contributed to llama.cpp.
  6. JavaScript: Cloudflare Workers, such as a data proxy for Polynode.
  7. Solidity: Camera Person contracts that split every sale on-chain.
  8. Tokio: Async runtime for every Polynode Rust service.
  9. Axum: Polynode's REST and WebSocket endpoints.
  10. NestJS: Venue modules and execution handlers in agg.market's API.
  11. Prisma: agg.market migrations, including a non-blocking index rebuild.
  12. Node.js: agg.market's API and executor, and Polynode's chain indexers.
  13. Deno (Supabase Edge Functions): Polynode billing and key-management Edge Functions.
  14. Bun: One-off data migration jobs at Polynode.
  15. PostgreSQL: Multi-terabyte Polynode databases with 1.2B+ fills.
  16. PgBouncer: Connection pools in front of Polynode's Postgres.
  17. Redis: Polynode API keys, rate limits, live market state, streams.
  18. SQLite: Mithril chats and on-device full-text and vector search.
  19. PostgREST: Polynode usage metering data for billing and dashboards.
  20. WebSockets: Polynode streams of decoded Polymarket orders and trades.
  21. Apache Kafka: agg.market venue integrations on its Kafka pipeline.
  22. Hetzner: Polynode's bare-metal servers for real-time ingestion.
  23. Cloudflare: DNS, TLS and abuse protection for Polynode's public domains.
  24. Cloudflare Workers and R2: MASHBOX app downloads, gated by the player's pass.
  25. Cloudflare Pages: mashbox.gg and the Return of the Colossi site.
  26. Google Cloud TPU: MASHBOX Labs model research on v5p and v6e spot capacity.
  27. Google Cloud Storage: Research weights, compile caches and queues near the TPUs.
  28. Amazon Web Services (ECS, MSK): agg.market backend services on ECS with Amazon MSK.
  29. Docker: Polynode's Postgres databases and supporting services.
  30. Caddy: Polynode's TLS edge and blue/green traffic switches.
  31. Linux and systemd: Every Polynode service as a systemd unit, with runbooks.
  32. Supabase: Polynode accounts and billing; self-hosted MASHBOX accounts.
  33. Pulumi: agg.market infrastructure code for new venues in production.
  34. Kubernetes: Local k3d clusters to run and test agg.market's services.
  35. OpenTofu: Infrastructure-as-code adoption for agg.market's AWS stack.
  36. GitHub Actions: Polynode CI: lint, contract tests, SDK signature tests.
  37. Harness: agg.market release pipelines with OIDC access checks.
  38. Playwright: End-to-end browser checks of the Return of the Colossi game.
  39. Grafana: Polynode dashboards for latency, per-key usage and capacity.
  40. Grafana Loki: Polynode logs, to tie latency spikes to a customer key.
  41. PostHog: Sign-up and checkout analytics on the Polynode dashboard.
  42. React: The Polynode dashboard for sign-up, API keys and billing.
  43. Vite: Builds for the Polynode dashboard.
  44. Tailwind CSS: Styling for the Polynode dashboard.
  45. Next.js: UI changes to agg.market's shared components for its web apps.
  46. three.js: Return of the Colossi, a browser game.
  47. WebGPU: Rendering for Return of the Colossi.
  48. WebAssembly: The MASHBOX Rust engine compiled for the browser.
  49. WebRTC: Direct player connections for MASHBOX browser multiplayer.
  50. SwiftUI: The agg.market app UI, adaptive for iPhone, iPad and Mac.
  51. App Store and TestFlight: Mithril on the App Store; agg.market beta on TestFlight.
  52. Apple Foundation Models: Apple's on-device model in Mithril, next to open models.
  53. React Native and Expo: The first versions of Mithril.
  54. Tauri: The MASHBOX Windows app that installs and launches the engine.
  55. NSIS: The signed MASHBOX Windows installer.
  56. WalletConnect (Reown): Ethereum wallet sign-in in the agg.market app.
  57. llama.cpp: On-device GGUF models in Mithril; model support sent upstream.
  58. JAX: MASHBOX Labs TPU inference and training research code.
  59. Pallas: Custom TPU kernels in MASHBOX Labs research; fixes sent to JAX.
  60. XLA: Compiling and profiling on TPU in research; compiler bugs reported.
  61. Flax and Optax: Fine-tuning research runs on TPU.
  62. MaxDiffusion: Diffusion models on TPU in research; fixes sent upstream.
  63. PyTorch: Reference models to check and export weights for TPU ports.
  64. Hugging Face Hub: Mithril model downloads with memory-fit and SHA-256 checks.
  65. ONNX Runtime: On-device text embeddings in early Mithril versions.
  66. NVIDIA Parakeet: On-device speech recognition in Mithril.
  67. Whisper (ExecuTorch): On-device speech-to-text in Mithril and Mithril Whisper.
  68. Stable Diffusion: Custom models for AI video in an AMC documentary.
  69. Claude Code and Codex: Parallel coding agents behind review and verification gates.
  70. LLM APIs (OpenAI, Anthropic): Quantish agents that traded prediction markets.
  71. Model Context Protocol: MCP servers that let Quantish agents read markets and trade.
  72. Bevy: MASHBOX's Rust game engine, mixing worlds with multiplayer.
  73. Unreal Engine 5: World and simulation prototypes at MASHBOX Labs.
  74. Blender: Headless asset generation for Return of the Colossi.
  75. Jolt Physics: Climbing and collisions in Return of the Colossi.
  76. Polygon: Real-time decoding of Polymarket activity for Polynode.
  77. Alloy: Event and signed-order decoding in Rust, with parity tests.
  78. viem and ethers: Order signing in Polynode's TypeScript SDK.
  79. Chainlink Data Streams: Live reference prices for crypto-round markets (Polynode).
  80. The Graph (graph-node): Self-hosted subgraphs to rebuild Polymarket history.
  81. Envio HyperIndex: Indexers for live P&L and combo markets (Polynode).
  82. Goldsky: Subgraph data for backfills and position cross-checks.
  83. Hyperliquid: An indexer and API for HIP-4 prediction markets.
  84. Stripe: Polynode subscriptions, with webhooks that provision API keys.
  85. Mintlify: Polynode's public API docs and changelog.
  86. Telegram Bot API: Polynode production alerts.
  87. Railway: Hosting for Quantish's agent services and databases.