Tyler Denniston Email & Phone Number

Chapel Hill, Nc, Us

Mountain View, Ca, Us

Cambridge, Ma, Us

Accepted Director of Engineering role with a new funding round, and helped scale the team from 3 to 10 engineers. Leadership role in managing our development efforts based on business priorities in consultation with CEO. Made critical architecture and API decisions for the core C++ codebase.In addition to continued focus on performance engineering in our core C++ codebase, I led the design and development of a high performance genomics variant call data store. The TileDB-VCF variant store supports efficient storage and retrieval of variant call data, using single- (threaded) and multi-node parallelism (via AWS batch) for high performance ingestion and export.

Cambridge, Ma, Us

TileDB is a new storage format and engine for efficient storage and retrieval of dense and sparse multidimensional array data. I joined TileDB as the second engineering hire, and had a large part in shaping our codebase and engineering processes, including our release process, documentation, code style, and other foundational components.Most of my engineering work at TileDB was in the core C++ storage engine codebase, including parallelization of the core read path, optimizing single and multithreaded performance of reads and writes, implementing the performance-critical tile filtering pipeline, and general feature implementation and bugfixing. Additionally, I implemented many user-facing applications using TileDB as a library in a variety of domains such as geospatial and LiDAR data, and genomics/bioinformatics data, and image procesing.

After finishing graduate school, I founded a small (solo) software business to sell a product that I conceived of during my time in academia. The software, Vexlio, makes it easy to quickly make precise and good-looking diagrams for technical, academic, or business publications and presentations. Essentially, I wrote the software that I wished had existed when writing my thesis, papers, and other presentations. Vexlio has a robust auto-snapping system, automatic cropping PDF export, an integrated LaTeX equation editor, and a Lua API for drawing diagrams with code, among other features. I wrote Vexlio from scratch, and created the cloud-side business infrastructure required to market and sell it, including an auto-updater, license activation system, website and sales pipeline, and customer database schema. The public launch post reached the front page of Hacker News and Product Hunt.

Cambridge, Ma, Us

As a graduate research assistant in the COMMIT (Compilers @ MIT) group with Professor Saman Amarasinghe, I lead the research and development effort for Distributed Halide, a domain-specific language for distributed-memory execution of stencil pipelines for terapixel image processing and scientific simulation. I extended the existing Halide compiler to generate MPI calls for the distribution of data as well as computation in the stencil program. The novel approach we took adhered to the Halide philosophy of separating algorithmic details from implementation, which allows programmers to take a shared-memory stencil pipeline written in Halide and rapidly experiment and iterate to discover an efficient strategy of distribution. I evaluated distributed Halide on nine representative benchmarks up to 16,384 cores on the NERSC "Cori" supercomputer.

Palo Alto, Ca, Us

During my internships at VMware, I was a member of the Monitor group. I worked closely with a mentor to develop a novel virtual machine checkpointing system in the VMware ESXi hypervisor (vmkernel). Our checkpointing system used a "lazy" approach to greatly reduce the time-to-useful-response of a guest during restoration from a checkpoint. Our approach serialized guest main memory according to the access pattern of the guest while the checkpoint was being taken, to optimize temporal and spatial locality during checkpoint restore. During checkpoint restore, the guest would access its memory pages in roughly the same order, taking advantage of locality in streaming disk access to read the pages from the checkpoint file on disk. To ensure bounded time to complete the checkpoint, a background worker thread walked guest main memory touching pages not already saved. The background thread could be dynamically throttled to ensure minimal resource contention with the guest's accesses.

Palo Alto, Ca, Us

Boston, Ma, Us

I worked as an undergraduate research assistant in the High Performance Computing Lab with Professor Gene Cooperman. There I was a member of a small research team developing FReD, a reversible or "time travelling" debugger based on a checkpoint-restart and deterministic record-replay mechanism. I developed the initial version of the deterministic record-replay system that intercepted and logged the system calls and lock acquisitions of the program under test, enforcing the same ordering and return values during subsequent replays of the program's execution. I also helped develop the Python script to wrap the underlying debugger, allowing us to add our reversibility layer without modifying the debugger itself.

Somerville, Massachusetts, Us

As an intern at Basis, I was a member of the NLP software development team responsible for an entity-extraction library. I was primarily responsible for quality assurance including writing a new regression test framework for the evaluation of the trained NLP model's performance and accuracy, fixing small bugs in the library, and verifying bugs fixed by my team members.

Master Of Science - Ms, Computer Science

Bachelor Of Science - Bs, Computer Science