Product Perfect

ECL (Enterprise Control Language) is a declarative, data-centric programming language developed by HPCC Systems. It is primarily used for big data processing on the HPCC platform, an open-source, massive parallel-processing computing platform for big data manipulation and analysis. ECL is designed to be easy to read and understand, with a syntax that allows programmers to manage and manipulate large volumes of data. It supports a data-first approach where the programmer defines what they want the output to be and the language handles how it is achieved. This makes ECL particularly suitable for complex data queries and tasks in data-intensive applications.

Ask the right questions secure the right ECL (HPCC Systems) talent among an increasingly shrinking pool of talent.

First 20 minutes

General ECL (HPCC Systems) app knowledge and experience

The first 20 minutes of the interview should seek to understand the candidate's general background in ECL (HPCC Systems) application development, including their experience with various programming languages, databases, and their approach to designing scalable and maintainable systems.

How would you define ECL in HPCC Systems?

ECL is a declarative, data-centric programming language designed for big data processing on HPCC Systems platform. It's used to define and manipulate data on a massive scale in a simple and efficient manner.

What are the main components of HPCC Systems?

HPCC Systems has two main components: Thor, the data refinery engine, and Roxie, the data delivery engine.

Describe the difference between Thor and Roxie in HPCC Systems.

Thor is the batch data processing engine, used for data cleaning and ETL tasks. Roxie, on the other hand, is a rapid data query engine, used for real-time data querying and reporting.

How would you handle data skew in ECL?

Data skew can be handled in ECL by using the DISTRIBUTE function to redistribute the data evenly across all nodes. Additionally, the SKEW function can be used to identify the degree of skewness in the data.

What are some of the key features of ECL?

ECL has several key features such as its declarative nature, built-in support for parallel processing, and its ability to handle complex data transformations with ease.

The hiring guide has been successfully sent to your email address.

Oops! Something went wrong while submitting the form.

What you’re looking for early on

Does the candidate have a solid understanding of ECL and HPCC Systems?

Has the candidate demonstrated problem-solving skills?

Is the candidate able to communicate effectively?

Does the candidate have experience with data-intensive computing?

Next 20 minutes

Specific ECL (HPCC Systems) development questions

The next 20 minutes of the interview should focus on the candidate's expertise with specific backend frameworks, their understanding of RESTful APIs, and their experience in handling data storage and retrieval efficiently.

Describe the difference between ECL and SQL.

While both are declarative languages, ECL is specifically designed for big data processing and has built-in support for parallel processing. SQL, on the other hand, is a general-purpose query language.

How would you optimize an ECL code for better performance?

ECL code can be optimized by minimizing data movement, using appropriate data structures, leveraging built-in functions, and avoiding unnecessary computations.

What are the different types of JOINs in ECL?

ECL supports several types of JOINs including INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN, and SELF JOIN.

Describe the difference between a SET and a DATASET in ECL.

A SET in ECL is a collection of homogeneous data elements, while a DATASET is a collection of heterogeneous data records.

How would you handle missing data in ECL?

Missing data can be handled in ECL by using the IFNULL function to replace null values with a default value.

The hiring guide has been successfully sent to your email address.

Oops! Something went wrong while submitting the form.

At this point, a skilled ECL (HPCC Systems) engineer should demonstrate strong problem-solving abilities, proficiency in ECL (HPCC Systems) programming language, and knowledge of software development methodologies. Red flags include lack of hands-on experience, inability to articulate complex concepts, or unfamiliarity with standard coding practices.

Digging deeper

Code questions

These will help you see the candidate's real-world development capabilities with ECL (HPCC Systems).

What does the following ECL code do?
IMPORT STD;

STRING20 name := 'John Doe';

STD.System.Thorlib.Trace(name);
This code imports the standard library, declares a string variable 'name' with a value of 'John Doe', and then uses the Thorlib.Trace function to write the value of 'name' to the system log.
What will be the output of the following ECL code?
SET OF STRING10 MySet := ['apple', 'banana', 'cherry'];

OUTPUT(MySet);
The output of this code will be a set of strings containing 'apple', 'banana', and 'cherry'.
What does the following ECL code do?
DATA person := {UNSIGNED id, STRING20 name, STRING20 city};

person p1 := {1, 'John Doe', 'New York'};

person p2 := {2, 'Jane Doe', 'Los Angeles'};

DATASET(person) people := [p1, p2];

OUTPUT(people);
This code defines a data structure 'person' with fields 'id', 'name', and 'city'. It then creates two instances of 'person', 'p1' and 'p2', and puts them into a dataset 'people'. The OUTPUT function is then used to output the dataset.
What does the following ECL code do?
IMPORT STD;

STRING20 name := 'John Doe';

STD.System.Thorlib.Trace(name);

WAIT(1);
This code imports the standard library, declares a string variable 'name' with a value of 'John Doe', uses the Thorlib.Trace function to write the value of 'name' to the system log, and then pauses execution for 1 second using the WAIT function.

Wrap-up questions

Final candidate for ECL (HPCC Systems) Developer role questions

The final few questions should evaluate the candidate's teamwork, communication, and problem-solving skills. Additionally, assess their knowledge of microservices architecture, serverless computing, and how they handle ECL (HPCC Systems) application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What are the different data types supported by ECL?

ECL supports a variety of data types including boolean, integer, real, string, unicode, data, and complex data types like record, dataset, and set.

Describe the difference between a FUNCTION and a MACRO in ECL.

A FUNCTION in ECL is a reusable piece of code that returns a value, while a MACRO is a reusable piece of code that does not return a value.

How would you implement recursion in ECL?

Recursion in ECL can be implemented by defining a FUNCTION that calls itself. However, due to the parallel nature of ECL, recursion should be used sparingly and with caution.

ECL (HPCC Systems) application related

Product Perfect's ECL (HPCC Systems) development capabilities

Beyond hiring for your ECL (HPCC Systems) engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in ECL (HPCC Systems) projects, and can engage in multiple capacities.

ECL (HPCC Systems) Consultive assessments

ECL (HPCC Systems) Application Conversion Assessment ECL (HPCC Systems) Application Integration Assessment ECL (HPCC Systems) Data & Database Integration Assessment

Custom ECL (HPCC Systems) development projects

Custom ECL (HPCC Systems) App Conversion ECL (HPCC Systems) Custom App Development Process App UI Design for ECL (HPCC Systems) Facelifts

Hiring guide for ECL (HPCC Systems) Engineers

ECL (HPCC Systems) Developer Hiring Guide

What you’re looking for early on

The ideal back-end app developer

What you’re looking to see on the ECL (HPCC Systems) engineer at this point.

ECL (HPCC Systems) Consultive assessments

Custom ECL (HPCC Systems) development projects