Consulting through Lazer Technologies · Taking on contract work
Full-stack engineer in Los Angeles. Most recently I built SwishX, a marketplace for sealed packs of graded sports cards, and the Solana side of Glacis Labs’ Airlift bridge.
SolanaEthereum
Intro
I started in consulting at West Monroe, where I worked on Con Edison’s intranet and Coinbase’s NFT beta. In 2022 I spent nights and weekends building raffles, staking sites and holder portals for Solana NFT communities, then spent about six months as founding engineer at Indie-Pop and about two years at Gavel on billing and document automation.
2019
Building since
15
Case studies
9
White-label Solana deployments, 2022–23
2
Bridge protocols behind one SDK
Place
Los Angeles
Taking on contract work
Now
Senior Software Engineer, Consultant
Solana mainnet slot, live
Reading the chain…
Education
Résumé
01 / 06
Sole architect and builder, via Lazer Technologies
SwishX sells sealed packs of graded sports cards. I architected and built it, from the pack-opening animation to the double-entry ledger that tracks every balance.
Live
02 / 06
Owned the Solana integration layer, via Lazer Technologies
Glacis Labs' bridge already worked on EVM chains. I built the Solana side, a TypeScript SDK that quotes and sends over Wormhole or LayerZero and fits large transfers under Solana's 1,232-byte limit.
Verified on mainnet
03 / 06
Built the Position Simulator, freelance
As a freelancer I built the Position Simulator on Orca's pool pages. It shows a liquidity provider their PnL across a price range before they deposit anything.
Live on orca.so
04 / 06
Freelance Solana developer, leading a small team
I led a small team building raffles, a spin-the-wheel game and staking sites for Solana NFT communities like Baby Ape Social Club and Sol Yetis. We built each one once and re-skinned it for every collection. We also made a holder portal for Catalina Whale Mixer.
Archived
05 / 06
Built the launch site and the SeaDrop contracts, via Lazer Technologies
Soulbound memberships and gift minting on SeaDrop, and a launch site with a layered parallax hero. It launched on OpenSea, and OpenSea featured it.
Launched 2025
06 / 06
Full-stack software engineer
At Gavel, a no-code legal document-automation product, I built billing and plan gating, owned the Python generator every workflow runs through, and built the AI review screen.
Gavel was acquired by Relativity in 2026
via Lazer
Led the internal pre-audit review of four Anchor programs, in an 11-day sprint.
Indie-Pop
One sign-in across six methods and three chains, with compressed NFT minting and a no-code page builder.
via West Monroe
Contributed to the purchase flow and the contract and royalty management UI for Coinbase's NFT beta in 2022.
An open-source Solana wallet extension where the popup never holds a keypair.
Bookable expeditions on Shopify. Trip dates are variants, so Shopify's own inventory enforces capacity.
Small demos that go with the case studies. They run in the browser, and you don’t need a wallet.
Position PnL across a price range
Set a deposit and a price range, then move the ending price.
If you deposited between and , and SOL ended at after …
you’d hold $959.87: +$169.37 on the deposit, −$146.29 against simply holding. In range 165 of 180 days.
Fees and rewards aren’t modeled, so this only shows the part of PnL that comes from the price and your range. The path is SOL’s real daily price over the last 180 days, tilted smoothly to finish at your ending price. Price data: CoinGecko, 2026-04-03 to 2026-09-29 (USDC taken as $1), fetched 2026-09-29.
This is my own re-creation of the math, not Orca’s code.
Fitting a bridge transfer into Solana’s v0 transaction limit
Move account keys into the lookup table and watch the size fall.
1,316 B
84 B over the v0 limit: this transaction fails
33 keys in the transaction · 0 in the lookup table
In the transaction32 B per key · 33
Address lookup table1 B per index · 0
Empty. The first key you move costs more than it saves: the transaction also has to name the table.
Before: 1,316 B with every key in the transaction. After: 482 B with all 28 shared program accounts in one lookup table. The quote matched what the transfer actually cost, to the lamport.
Legacy and v0 transactions are still capped at 1,232 bytes. The v1 format, on mainnet since Sept 15, 2026, raised the cap to 4,096 and doesn’t use lookup tables. Airlift shipped on v0, with Address Lookup Tables, in 2025.
Source: solana.com: larger transaction sizes · checked 2026-09-29
Illustrative, computed from the Solana wire format.
A simplified picture of the two message paths Airlift’s SDK chooses between.
Two buyers, one card
Press Race to send two buyers for the last card.
Buyer A
Order confirmed
Cards left
−1
Row unlocked
Buyer B
Order confirmed, but the card is gone
SELECT stock → 1Cards left: 1SELECT stock → 1Cards left: 11 > 0 ✓ · chargeCards left: 11 > 0 ✓ · chargeCards left: 1UPDATE stock = stock − 1 → 0Cards left: 0UPDATE stock = stock − 1 → −1Cards left: −1Oversold: two paid orders for one card, stock −1.
A generic demo of the race a marketplace checkout has to handle, not client code.
The popup and the approval window only send requests to the worker. Neither one ever holds a keypair.
Used in SwishX, Orca, Gavel, House of Pranksy
Used in SwishX, Gavel, Coll3ctibles
Used in Glacis Airlift, Sorare, House of Pranksy, community tooling, Cinder Wallet
Used in SwishX, Gavel
Used in SwishX, Gavel
Used in Sorare, House of Pranksy, Cinder Wallet, SwishX
Freelance Shopify developer
Senior Software Engineer, Consultant
Author and maintainer, Cinder Wallet
Software Engineer
Founding Engineer
Freelance Solana developer
Software Developer (contract)
Software Engineer, then Senior Software Engineer
Computer Science and blockchain
# Casey Charlesworth
Full-stack engineer in Los Angeles. They/them.
## Now
Senior Software Engineer, Consultant · Lazer Technologies · since 2025
Taking on contract work.
## Education
- B.E. Computer Science, University of Illinois Chicago, 2019 (minor in Computer Engineering)
- Blockchain Fundamentals, UC Berkeley, 2022
## Elsewhere
- GitHub: [freyja-934](https://github.com/freyja-934)
- LinkedIn: [casey-charlesworth](https://www.linkedin.com/in/casey-charlesworth)
If you're hiring, or have something you want built, email me. I'm taking on contract work, and I usually reply within a couple of days.