John Kelly — Staff Software Engineer

Staff software engineer specializing in global scale networks and distributed compute platforms. 8 years designing and operating production systems serving millions of requests per second and petabytes of data per day. spanning in-kernel packet processing, L4/L7 load balancing, bare-metal server automation, and cloud network architecture.

SKILLS

NETWORK

BGP, IPVS, Nginx, HAProxy, Envoy, CDNs, Internet & Web Protocols, Linux Kernel Networking, XDP/eBPF, WireGuard, VyOS

COMPUTE

KVM/Firecracker, Proxy-Wasm/WASI, Kubernetes, VMware, Proxmox, Ceph

INFRA

GCP, AWS, Postgres, Cassandra, Varnish, Packer, Terraform, Ansible, Saltstack

CODE

Rust, Python, Go, Java, TypeScript, C++

EXPERIENCE

Discord

San Francisco, CA · Remote

Lead Staff Software Engineer // Traffic Infrastructure

Dec 2025 — Present

—Defined the network architecture and cross-cloud connectivity requirements for Discord's initial multi-cloud strategy, driving alignment across engineering, finance, and executive leadership

—Built client-side network error reporting that surfaces regional and ISP-specific outages affecting users globally, giving policy and CX teams actionable path-quality signal that server-side telemetry cannot see

—Designed an HMAC-signed header scheme for authenticating end-user requests at the CDN edge, enabling granular rate limiting and tiered abuse prevention based on client identity

Staff Software Engineer // Media Infrastructure

Feb 2024 — Dec 2025

—Led multi-CDN initiative serving petabytes of static assets daily, reducing latency 15% and egress bandwidth costs 30% through measurement-driven provider steering

—Developed internal content-addressable storage system enabling strong versioning of in-app assets uploaded to the global CDN, reducing developer friction and allowing immutable caching of highly fetched content at the edge.

—Optimized the mobile attachment upload flow with more efficient image compression, achieving 30% faster upload latency

Senior Software Engineer // Traffic Infrastructure

Jul 2022 — Feb 2024

—Migrated all inbound API traffic reaching ~2M RPS at peak to an Envoy-based proxy fleet, allowing for more precise traffic steering and circuit-breaking/bulkheading at the edge.

—Drove service mesh adoption by migrating 90% of core production services across 12+ infrastructure and product teams, migrating all production services from legacy client-side routing to Envoy proxy sidecars

—Designed and built a self-service traffic platform with TypeScript configuration, reducing new service infrastructure provisioning time 75%

Squarespace

New York, NY

Software Engineer // Traffic Infrastructure

Dec 2019 — Jul 2022

—Built a custom DDoS detection and enforcement engine using XDP/eBPF, classifying and dropping attack traffic in-kernel at the earliest point in the datapath before it consumed userspace proxy capacity

—Replaced legacy hardware L4 load balancers with a software IPVS solution using direct server return (DSR), improving tail latencies and high-availability failover across on-prem and cloud footprints

—Reduced TLS handshake latency 15% by designing and building a new L7 proxy to offload TLS termination at the edge

Software Engineer // Compute & Storage

Jul 2018 — Dec 2019

—Automated the hypervisor hardware lifecycle across a fleet spanning 20+ racks in two data centers, spanning iPXE/iDRAC bare-metal provisioning through Packer/Ansible image baking, with rebuilt images rolled out fleet-wide daily

—Operated and capacity-planned 20+ Kubernetes clusters across on-prem data centers and cloud, alongside VMware virtual machine infrastructure and Ceph storage clusters

—Built a Kubernetes operator to automatically provision and optimally schedule virtual machines, reducing developer toil and improving fleet resource efficiency

—Cut base image build time 80% by reworking the Packer-based image pipeline

PROJECTS

AS401898 — Autonomous System & Multi-Tenant Network Fabric

Ongoing · Colocation, home, and cloud

—Operate a production ASN with a direct ARIN IPv6 allocation (/40), running eBGP with an upstream transit provider from a colocated Proxmox/VyOS deployment

—Designed a multi-tenant addressing plan with VRF-per-tenant isolation and WireGuard overlays spanning colocation, home, and cloud environments

—Built a Python DSL that generates Ansible inventory from a declarative model of the fabric, making router and host provisioning repeatable across the estate

Sandboxed Execution — Firecracker / WASM Runtime

Draft — to be written

—What the sandbox runs, and for whom.

—The isolation boundary and why Firecracker or WASI was the right one.

—A number: cold-start time, density per host, or throughput.

EDUCATION

Bachelor of Science, Computer Science

May 2018

Stevens Institute of Technology — Hoboken, NJ

CONTACT

linkedin.com/in/johnrobertkelly

GITHUB

github.com/nulltrope

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