Arindam Paul builds the kind of trading infrastructure where nanoseconds matter — ring buffer architectures, NUMA-aware threading, and JVM tuning that eliminates garbage collection pauses from the critical path entirely.
In high-frequency trading, latency is the product. Every microsecond saved on the critical path — from market data receipt to order acknowledgement — translates directly into edge. Arindam Paul has spent more than two decades building systems where this arithmetic is the only one that matters.
At IMC Financial Markets, one of the world's leading options market makers, Arindam built and owns the low-latency trading infrastructure that connects to more than ninety global venues. The systems process market data, run pricing logic, generate orders, and receive exchange acknowledgements — all within a sub-millisecond round trip. This is not a benchmark. It is the live production number, sustained across high-throughput market sessions in multiple timezones simultaneously.
The foundational design pattern for low-latency trading systems is the ring buffer: a fixed-size, pre-allocated circular queue that avoids dynamic memory allocation, eliminates lock contention, and exploits CPU cache locality. Arindam's implementations are grounded in the LMAX Disruptor model — the seminal ring buffer design that demonstrated Java could compete with C++ in latency-sensitive environments when the JVM is configured correctly and allocation is eliminated from the hot path.
Lock-free data structures extend this principle: where synchronization is unavoidable, compare-and-swap operations and memory barriers replace mutex contention. Arindam designs systems where threads communicate exclusively through shared ring buffers with sequenced visibility guarantees, eliminating the unpredictable latency spikes that come from lock acquisition and context switching.
Java is the dominant language in institutional trading infrastructure. Its portability, ecosystem, and developer productivity are well understood. What is less well understood outside of low-latency engineering is how dramatically JVM behavior can be shaped by configuration and coding discipline.
Arindam's JVM performance work operates at several levels. At the allocation level: designing hot-path code that generates zero garbage — no object creation, no boxed primitives, no stream operations — so the garbage collector is never triggered during trading hours. At the JIT level: structuring code to remain in the JIT compiler's fast path, avoiding deoptimization traps from megamorphic call sites and uncommon traps. At the startup level: pre-warming critical paths and loading all classes before market open so the JIT has compiled everything that matters before the first order is sent.
GC tuning goes further: ZGC and Shenandoah for concurrent collection when some allocation is unavoidable; explicit off-heap memory management via sun.misc.Unsafe and Chronicle Map for large datasets that must not be visible to the collector at all.
The lowest latencies are achieved by treating the hardware as a first-class constraint rather than an abstraction. Arindam designs systems with explicit CPU affinity: critical trading threads are pinned to specific physical cores, isolated from the OS scheduler, and prevented from migrating. This eliminates cache-miss latency from cross-core thread migration and the scheduling jitter that comes from sharing cores with other processes.
NUMA-aware memory allocation ensures that threads access memory on the same NUMA node as their assigned CPU. In multi-socket systems, cross-node memory access can add tens of nanoseconds per access — a significant cost on the critical path when repeated millions of times per second. Arindam's systems allocate ring buffers and working memory on the NUMA node local to the thread that will use them.
At the network layer, DPDK (Data Plane Development Kit) and kernel bypass networking eliminate the OS network stack from the receive path. Market data arrives directly into application memory without a kernel context switch, removing a significant and variable source of latency. Combined with hardware timestamping for precision latency measurement, this yields a complete picture of where time is spent across the full exchange round trip.
For a detailed narrative of how these systems were designed and what it is like to build trading infrastructure at this scale — latency budgets, the engineering decisions that matter, and the operational reality of maintaining sub-millisecond systems across 90+ global venues — read What It's Like to Build Systems That Trade Billions.
For the full context of Arindam's role at IMC Financial Markets, including the exchange connectivity and market data infrastructure that these systems depend on, visit the IMC experience page.
Available for Low-Latency Engineering Roles
Arindam is open to senior and principal low-latency engineering positions, head of trading technology roles, and technical leadership engagements at HFT firms, prop trading shops, and market makers. Target geographies include Singapore, Hong Kong, Dubai, and New York. See hiring details or discuss an engagement.