Hadoop Security – Role Based

October 20th, 2014 / Tales from a Trading Desk

Cloudera offer a number of interesting blog articles on Hadoop security – Impala using Apache Sentry.  From an enterprise perspective, creation of a data lake will inevitably require a clean security approach from day 1.

Shipping Quality Code

October 15th, 2014 / Tales from a Trading Desk

Scripting and Learning by Shipping both offer good reads on shipping quality code.  Its also nice to see that SAFe also has view on code quality, and the importance of Test First.

Test-first methods can be further divided into Test-Driven Development (TDD) and Acceptance-Test Driven Development (ATDD). Both are supported by Test Automation, which is required in support of Continuous Integration, team velocity, and development efficiency.

Beauty of Testing (Steven) offers a few home truths which unfortunately are seemingly lost in the rush to make a production release by people not aware of the complexity of software engineering (and it not being an exact science):

Single Dealer Platforms – Another Day Another View

October 15th, 2014 / Tales from a Trading Desk

WallStreet & Technology offers a view on Single Dealer Platforms (SDP).  Over the last few years there have been a number of articles stating that SDP’s will either take over the world, or are a dying breed.  The net out of this latest article is unsurprisingly a view that Single Dealer Platforms and Multi Dealer Platforms will be combined by either banks or clients to offer a subset of services based on the clients needs – best of breed (effectively a type of mashup).

Engineering Management

October 15th, 2014 / Tales from a Trading Desk

Great post from Slava @ReThinkDB.  Some great lessons.  32 – news doesn’t age well! 21 – Leadership is important

Further, Slava offers some view on project management – of particular note, treat big projects with care.  Of particular importance:

build the absolute most minimal version that solves the customer’s problem.

DDD – Part 3

September 30th, 2014 / Tales from a Trading Desk

Few relevant postings to read:

State Replication

September 30th, 2014 / Tales from a Trading Desk

A colleague pointed me at a few interesting articles (Replicant) centred around state replication. For a long time I’ve been interested in state replication – I’ve blogged here and there about it over the years. The ability for each replicate to accept change, and propagate change to all replicas ensuring consistency is an interesting problem to solve. Such solutions off interesting scalability options in distributed applications.

Mencius  offer more of what I’m interested – single/multi leader

Implementing Domain-Driven Design – Part 2

September 30th, 2014 / Tales from a Trading Desk

Continuing with Vaughn’s book, page 22 table 1.4 offer a nice view of writing code that models the business – physical and conceptual domains.  Page 25 hits the nail on the head with reference to software engineers not being able to pursue technologies and techniques just because they sound cool – well said Mr Vernon!

Page 33 touches on the issues of data-centric models, compared to business domain behaviours.  All to often we see in code bases that the data payloads have become some warped domain model within the code base, leaking though every layer possible.

Estimation – The Guessing Game

September 20th, 2014 / Tales from a Trading Desk

InfoQ offers an interesting read on agile planning and estimation. Here are a few key quotes :)

All numbers are based on assumptions. Your figures are only as good as your estimates and guesses – and there may be serious flaws in your assumptions.

If we approve a project based on a year’s worth of work, and we estimate it and we think it is all good, there is a lot of risk inherent in there. But also, and this is worse, we might ditch doing something really, really valuable for the company because we have clumped together all this value into a year-long project and we are making a really big decision – to go or no go – based only on that clump.

What happens when Non-Functional Requirements (NFR) are forgotten

September 18th, 2014 / Tales from a Trading Desk

“Behind the Curtain of the HealthCare.gov Rollout” offer a few excellent quotes.  I particularly like the quote around the number of concurrent users:

After the launch, HHS officials sharply criticized CMS’s management leading up to the launch of Healthcare.gov. Referencing an email in which a CMS official admits the system could not handle more than 500 concurrent users, Mr. Baitman wrote “Frankly, it’s worse than I imagined!” and Mr. Sivak replied, “Anyone who has any software experience at all would read that and immediately ask what the fuck you were thinking by launching.”

Data Collision

September 17th, 2014 / Tales from a Trading Desk

Oracle GoldenGate and HotCache offer an interesting (but expensive) solution to solving certain classes of problem.  Assuming an application stack that is Java, leveraging Oracle Coherence, backed by an Oracles database, where the application stack is installed in two locations, with the requirements for bi-directional replication of data, so each application sees the others data, and can perform actions on the data.  GoldenGate leveraging HotCache provides a mechanism to achieve replication, with the added benefit that not only does the data get replicated between databases (GoldenGate), but that Coherence state is updated as well (HotCache).

Scala Parser Combinators

September 16th, 2014 / Tales from a Trading Desk

Combinator coolness:

  • Parser combinators FTW
  • Playing with Scala Parser Combinator
  • External DSLs made easy with Scala Parser Combinators
  • Parsing sentences using Scala parser combinator

Implementing Domain-Driven Design

September 16th, 2014 / Tales from a Trading Desk

Eric’s Domain-Driven Design (DDD) book is unfortunately not seen enough on software engineers desks.  Hopefully, Implementing Domain-Driven Design will increase the usage of DDD.  Having started to read the book on the last flight, I think Vaughn makes a number of comments in the early pages that are spot on.  Specifically:

“General abandonment of good design and development practices in the Java community” (page xxvii)

“Scrum and other agile techniques are being used as a substitute for careful modelling, where a product backlog is thrust at developers as if it serves as a set of designs” (page xxvii)

BlackRock Aladdin – 25m lines of code

September 15th, 2014 / Tales from a Trading Desk

BlackRock’s Aladdin is an interesting platform, offering dedicated client environments amongst other things.  Anyone know what the codebase is written in?   Coupled of interesting reads on Aladdin:

  • BlackRock’s Aladdin: More Powerful Than Politics?
  • BlackRock’s Aladdin: genie not included

Protocol Buffer – Backward Compatibility

September 15th, 2014 / Tales from a Trading Desk

Worth remembering:

  • you must not change the tag numbers of any existing fields.
  • you must not add or delete any required fields.
  • you may delete optional or repeated fields.
  • you may add new optional or repeated fields but you must use fresh tag numbers (i.e. tag numbers that were never used in this protocol buffer, not even by deleted fields).

Apple Pay – $40 billion Slice

September 15th, 2014 / Tales from a Trading Desk

MoneyWeek has an interesting angle on the recent iPhone 6 announcement.  The game changer being Apple Pay.  This is Money offers a further view on Apple Pay.

Market share is however the influencer.  Could Google copy the concept, and with its market share?

Commodore PET – Blast From The Past

September 4th, 2014 / Tales from a Trading Desk

Some of us started on these, learning CECIL.


Scaling Agile

September 3rd, 2014 / Tales from a Trading Desk

A few interesting articles worth a read:

  • Scaling Agile at Gilt
  • Agile PMO – Triangle of Truth :)
  • The new user story backlog is a map


Distributed Systems

August 27th, 2014 / Tales from a Trading Desk

Few interesting articles recently on distributed systems:

  • The Space Between Theory and Practice in Distributed Systems
  • Distributed systems theory for the distributed systems engineer

Of particular interesting:

How you decide whether an event happened before another event in the absence of any shared clock. This means Lamport clocks and their generalisation to Vector clocks, but also see the Dynamo paper.

And then there is the coolness of state machines:

Distributed state machine replication (Wikipedia is ok, Lampson’s paper is canonical but dry).


Legacy Data

August 27th, 2014 / Tales from a Trading Desk

Dave McCrory has an interesting presentation on InfoQ which discusses enterprise platform as a service.  Slide 23 onwards discusses legacy data, and the issues associated with data consumption.  Master Data Management is also discussed in the deck.  Which leads to a New York Times article, “For Big-Data Scientists, ‘Janitor Work’ Is Key Hurdle to Insights”.

Data scientists, according to interviews and expert estimates, spend from 50 percent to 80 percent of their time mired in this more mundane labor of collecting and preparing unruly digital data, before it can be explored for useful nuggets.



Capital Market Big Data Use Cases

August 26th, 2014 / Tales from a Trading Desk

Couple of interesting use cases in this InfoQ video:

  • Broker-Dealer transaction history
  • Client Review
  • Customer Relations and Prospecting
  • Enterprise Credit Risk
  • Cluster Pricing

Clearly the presentation didn’t have time to get into Lambda architectures, Spark and more